• 제목/요약/키워드: Statistical assessment

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Seismic risk assessment of intake tower in Korea using updated fragility by Bayesian inference

  • Alam, Jahangir;Kim, Dookie;Choi, Byounghan
    • Structural Engineering and Mechanics
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    • 제69권3호
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    • pp.317-326
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    • 2019
  • This research aims to assess the tight seismic risk curve of the intake tower at Geumgwang reservoir by considering the recorded historical earthquake data in the Korean Peninsula. The seismic fragility, a significant part of risk assessment, is updated by using Bayesian inference to consider the uncertainties and computational efficiency. The reservoir is one of the largest reservoirs in Korea for the supply of agricultural water. The intake tower controls the release of water from the reservoir. The seismic risk assessment of the intake tower plays an important role in the risk management of the reservoir. Site-specific seismic hazard is computed based on the four different seismic source maps of Korea. Probabilistic Seismic Hazard Analysis (PSHA) method is used to estimate the annual exceedance rate of hazard for corresponding Peak Ground Acceleration (PGA). Hazard deaggregation is shown at two customary hazard levels. Multiple dynamic analyses and a nonlinear static pushover analysis are performed for deriving fragility parameters. Thereafter, Bayesian inference with Markov Chain Monte Carlo (MCMC) is used to update the fragility parameters by integrating the results of the analyses. This study proves to reduce the uncertainties associated with fragility and risk curve, and to increase significant statistical and computational efficiency. The range of seismic risk curve of the intake tower is extracted for the reservoir site by considering four different source models and updated fragility function, which can be effectively used for the risk management and mitigation of reservoir.

산업보건 위험성평가 기법의 현장 적용에 관한 연구 (A Study on the Field Application of Occupational Health Risk Assessment Method)

  • 정종득;유재흥;김윤희;정기효
    • 대한안전경영과학회지
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    • 제26권2호
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    • pp.79-86
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    • 2024
  • Scientific exploration of how occupational health risks relate with occupational illnesses are essential for mitigating health-related issues in industries. This study analyzed the risk scores obtained by occupational health risk assessments at 3,172 manufacturing companies and examined their effects on occupational illness. Statistical analyses revealed that companies with an occupational health manager (scored 89.1 out of 100) had significantly higher activity scores of health management compared to those without (78.2). However, companies with a history of occupational illness (79.1) or those classified as high-risk industries (85.2) had significantly lower activity scores than their counterparts (81.7, 87.3). In addition, regression analyses using factor analysis showed that latent risk factors such as cardiovascular disease/job stress, health management, and musculoskeletal problem significantly influenced the risk of occupational illness. The activity factors such as health management, work environment management, and regulatory complaisance significant impacted the reduction of occupational illness. The findings of this study can be used to improve the occupational health risk assessment method and utilized in effectively managing occupational risks in industries.

뇌졸중 환자에서 순환식 과제지향 프로그램이 기능 증진에 미치는 효과 (The Effects of a Task-Related Circuits Program on Functional Improvements in Stroke Patients)

  • 조규행;이석민;우영근
    • 한국전문물리치료학회지
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    • 제11권3호
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    • pp.59-70
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    • 2004
  • The purpose of this study was to propose a task-related circuits program for stroke patients and to test the difference in functional improvements between patients undergoing conventional physical therapy and those participating in a task-related circuits exercise program. The subjects were 10 stroke in-patients of the Korea National Rehabilitation Center in Seoul. We measured the following variables: Motor Assessment Scale (MAS), Berg Balance Scale (BBS), Tone Assessment Scale (TAS), speed of gait, rate of step, physiological costs index, age, weight, height, site of lesion, onset day and whether the subject participated in an exercise program. Collected data were statistically analyzed by SPSS 10.0/PC using descriptive statistics, Mann-Whitney U test, Wilcoxon rank sum test and Spearman's correlation. The results of the experiment were as follows: (1) In the pre-test and post-test for function, there was not a statistical significance between the group partaking in a task-related circuits program and the group of conventional physical therapy (p>.05). (2) In the MAS, BBS and speed of gait test, the group undergoing conventional physical therapy showed a statistical significance (p<.05). (3) In the MAS, BBS, speed of gait, PCI, TAS (passive, associated reaction, TAS total score), the group of task-related circuits program showed a statistical significance (p<.05). As a result, the group participating in a task-related circuits program had a more functional improvement than the group participating in conventional physical therapy. Therefore, an intervention recommended for a stroke patient would be a task-related circuits program consisting of a longer session of each task for a more improved functional recovery.

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다양한 평가기법을 이용한 금강 대권역의 수질 및 목표수질기준 달성도 평가 (Review on Water Quality and Achievement of Water Quality Goal by Various Evaluation Methods in Geum River)

  • 이재운;정혜성;윤정희;천세억
    • 환경영향평가
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    • 제17권6호
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    • pp.373-380
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    • 2008
  • The Ministry of Environment plans to improve quality of water which is achieved over 85% in rivers and 94% in lakes of the whole country as "Good Water" until 2015. Also, the law of evaluation of water quality and water quality goal were made newly. So, the water quality has evaluated by using new law since 2007. This study evaluated whether "Good Water" and" Water Quality Goal" were achieved or not in 22 middle-sized districts and major 10 lakes of Geum river. The achievement rates of rivers decreased and the achievement rates of lakes mostly were the same for 5 years. In 2007, the achievement rates of "Good Water" were 50% in rivers and 50% in lakes. The achievement rate of "Water Quality Goal" were 59.1% in rivers and 20% in lakes. The water quality in 2007 was evaluated worse than last year in case of rivers. The evaluations of Korea-Comprehensive Water Quality Index(K-CWQI) showed that achievement rates of "Water Quality Goal" were 81.8% in rivers and 0% in lakes. The statistical correlation analysis showed that correlations between BOD and COD were meaningful at the downstream, compared to upstream, generally. In case of lakes, correlations between COD and temperature were meaningful. Also, correlations between COD and Chl-a were meaningful. The Trophic State Index ($TSI_{KO}$) showed that the half of lakes are major over eutrophic status in lakes. These analytical methods such as K-CWQI, $TSI_{KO}$, statistical correlation analysis could be additionally helpful for evaluation of water quality and provide basis data for understanding characteristics of watershed in Geum river.

남한 지역 고해상도 기후지도 작성을 위한 공간화 기법 연구 (Applicability of VariousInterpolation Approaches for High Resolution Spatial Mapping of Climate Data in Korea)

  • 조아영;류지은;정혜인;최유영;전성우
    • 환경영향평가
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    • 제27권5호
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    • pp.447-474
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    • 2018
  • 본 연구의 목적은 다양한 지리통계학적 공간화 기법을 적용한 격자기후자료와 기상청에서 제공하는 국지예보모델(Local Data Assimilation and Prediction System, LDAPS) 격자기후자료를 비교 분석하여 남한 지역의 고해상도 격자기후지도 작성 방안을 모색하는 것이다. 2017년의 595개 기후관측자료 중, 80%의 지점자료를 이용하여 순간 온도와 1시간 누적강수량에 대한 격자기후자료를 생성하였고 나머지 117개의 지점자료를 검증에 이용하였다. ArcGIS10.3.1과 Python3.6.4을 이용하여 관측자료 및 DEM을 IDW, 공동크리깅, 크리깅에 적용한 후, 공간보간 결과를 3개 군집으로 나누어 검증하였으며 LDAPS 격자기후자료를 바탕으로 유역 별 패턴 비교를 수행하였다. 결과적으로 순간 온도의 공간화에는 고도를 부변수로 추가한 공동크리깅이, 1시간 누적강수량 공간화에는 IDW가 가장 적합하였다.

웹 기반 OPAC시스템 평가에서의 이용자 인지형태에 관한 연구 (A Study on the User Cognitive Styles in the Web-based OPAC System Evaluation)

  • 김희섭
    • 정보관리학회지
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    • 제18권3호
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    • pp.265-284
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    • 2001
  • 본 연구의 목적은 이용자의 인지유형과 그에 따른 웹기반 OPAC시스템 평가에 대한 상관관계를 알아보기 위한 것이다. 이용자들의 인지유형은 (1)Verbaliser/Imager와 (2) Wholist/Analytic으로 나누었고 웹기반 OPAC시스템의 (1)기능적인 측면과 (2)학습용이성 측면에 초점을 맞추어 평가를 하였다. 연구방법으로는 (1)사전조사를 위한 인터뷰, (2)주된 데이터 수집을 위한 질문지, 그리고 (3) 이용자의 인지형태 결정을 위해서 심리측정학(psychometric)방법을 사용하였다. 사전조사결과와 문헌의 리뷰에 근거하여 온라인 조사방법으로 (1)웹기반 온라인 질문지와 (2) Riding의 CSA(Cognitive Style Assessment)을 Sheffield 대학 캠퍼스 네트워크에 연결된 모든 PC에서 접속할 수 있게 온라인 테스트 환경을 구성하였다. 이 환경을 통하여 44명의 석.박사 학생들이 자발적으로 본 실험에 참가를 했으며, 이들로부터 수집된 데이터는 SPSS(Statistical Package for Social Science)를 이용하여 분석하였다. 통계분석에서 각 평가항목 변수들간의 상관관계분석을 위해서 피어슨(Pearson)의 상관계수 (Coefficient, f)를 사용하였다. 연구결과 개인의 인지형태와 웹기반 OPAC시스템 평가간에는 비교적 낮은 통계학적인 상관관계를 보였다.

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모아상호작용에 관한 연구 - 교육과 수유상황을 중심으로 (A study on the mother-infant intercation in teaching and feeding situation)

  • 조결자
    • 대한간호
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    • 제29권5호
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    • pp.54-68
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    • 1991
  • This study was conducted to provide the basic information for nursing intervention in infant teach. ing and feeding situation. The subjects were 30 pairs of mother and her infant(9 month) who were normally delivered at 3 university hospital in Seoul area. The data collection was conducted by observation using videotaperecord from September 27, 1989 to Feburary 26, 1990 in their home. The measulsement tools used by this researcher were Nursing child Assessment Teaching scale (NCATS) and Nursing child Assessment Feeding Scale(NCAFS) which was developed by Barnard. The higher sum of "yes" score means the higher mother-infant interaction level. Mother-Infant interaction behaviors in both sitution were based on 6 subcategories; sensitivity to cue, response to distress, social-emotional growth fostering, cognitive growth 'fostering, clarity of + cues, and responsiveness to parent. The data collected through above method were analyzed by mean and t-test and the results were as follows. 1. The sum of maternal behavior score was 40.2 out of 50.0 in teaching situation and 37.9 out of 50.0 in feeding situation. Out of the 4 subcategories on maternal behavior in both situation, the highest subcategory was shown by response to infant's distress and the lowest subcategory by cegnitive growth fostering. 2. The sum of infant behavior score was 14.7 out of 23 in teaching situation and 17.9 out of 26 in feeding situation. Out of the 2 categories on infant behavior in both situation, the highest sub categroy was shown by the clarity of infant's cue in both situation. 3. There was a statistical significance between father's educational level and mother-infant interaction in teaching situation; college group was higher than high school group, particulary in category of sensitivity to infant's cue and congnitive growth fostering. 4. There was a statistical significance in teaching situation between mother's educational level and mother-infant interaction;college group was higher than high school group, particulary sensitivity to infant cue, social-emotional growth fostering and cognitive fostering. 5. There was no statistical difference in between parent educational level and mother.infant interaction in feeding situation.situation.

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Quantitative assessment of depth and extent of notch brittle failure in deep tunneling using inferential statistical analysis

  • Lee, Kang-Hyun;Lee, In-Mo;Shin, Young-Jin
    • Geomechanics and Engineering
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    • 제21권2호
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    • pp.201-206
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    • 2020
  • A stress-induced brittle failure in deep tunneling generates spalling and slabbing, eventually causing a v-shaped notch formation. An empirical relationship for the depth of the notch to the maximum tangential stress assuming an equivalent circular cross-section was proposed (Martin et al. 1999). While this empirical approach has been well recognized in the industry and used as a design guideline in many projects, its applicability to a non-circular opening is worth revisiting due to the use of equivalent circular profile. Moreover, even though the extent of the notch also contributes to notch failure, it has not been estimated to date. When the estimate of both the depth and the extent of notch are combined, a practical and economically justifiable support design can be achieved. In this study, a new methodology to assess the depth as well as the extent of notch failure is developed. Field data and numerical simulations using the Cohesion Weakening Frictional Strengthening (CWFS) model were collected and correlated with the three most commonly accepted failure criteria (σ13, Dismaxc, σdevcm). For the numerical analyses, the D-shaped tunnel was used since most civil tunnels are built to this profile. Inferential statistical analysis is applied to predict the failure range with a 95% confidence level. Considering its accuracy and simplicity, the new correlation can be used as an enhanced version of failure assessment.

기능성 화장품의 인체시험 설계 및 통계적용 방법에 대한 고찰 (Investigation of the Study Plan and Statistical Method of Functional Cosmetics on Human Skin)

  • 서영경;고재숙;이원철
    • 대한화장품학회지
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    • 제39권2호
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    • pp.105-115
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    • 2013
  • 국내의 주름개선 혹은 미백 효능을 평가하기 위한 인체시험 방법은 식약청 가이드라인에 근거하여 시행 되어왔으며, 인체시험에서 육안평가 및 기기평가 결과에 대해 시험군과 대조군 간의 효과를 비교하기 위해서 unpaired t-test를 주로 이용하였고, 시술 전후의 효과를 비교하기 위해서 paired t-test를 이용하였다. 설문평가 결과에 대해서는 빈도분석을 이용한 기술통계법이 이용되고 있다. 미국 및 유럽의 임상 평가기관에서도 이와 유사한 시험법 및 통계분석 방법을 이용하고 있다. 그러나 동일 개체에 대하여 처치를 반복 적용하여 얻은 자료는 서로 관련성이 높아 이를 감안한 분석법을 적용해야 한다. 따라서 본 연구에서는 화장품 분야에서는 처음으로 기능성 화장품 중 주름 개선 및 미백 효능 시험의 육안평가 및 기기평가 자료에 대해 repeated measures ANCOVA (RM ANCOVA)와 repeated measures ANOVA (RM ANOVA)를 적용하여 통계 방법의 타당성 여부를 검증함으로서 현재의 인체시험 방법에 적합한 새로운 통계분석 방법을 제시하였다.

가축분뇨 관리를 위한 통합환경정보시스템 발전방안 (A Study on Comprehensive Environmental Information System for Livestock Manure Management in Korea)

  • 정동환;김용석;신진수;류덕희;조홍래;이태환
    • 환경영향평가
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    • 제22권2호
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    • pp.183-194
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    • 2013
  • The Ministry of Environment, Ministry of Agriculture, Fishery and Forestry, and Ministry of Construction, Transportation and Maritime Affairs are in charge of livestock manure management. There are national statistics regarding the livestock industry such as the National Pollution Source Survey, Livestock Statistic Survey, and Livestock-breeding Trend Survey. The current statistical data are focused on the scale of livestock breeding and the production of livestock manure using these data, but it is difficult to establish database due to lack of information. In order to plan relevant policies including management of livestock manure, the government established database systems such as the integrated information system of livestock manure, the integrated system of national infectious animal-disease prevention, and the Sae-ol public administrative system. We have tried to suggest improvements for the comprehensive environmental information system of livestock manure management by detecting problems in each level of the livestock manure life-cycle, making use of the existing systems, and considering the electronic transfer system of livestock manure. The services and functions of this comprehensive system include information of livestock farmers, the production, collection, transportation, and treatment of livestock manure, the area of agricultural land used for livestock manure, the report of approval and results on livestock manure products, management of statistical information, management of civil affairs, and relevant mobile application services. The system is made up of three processes: first, establishment of GIS-based management database of livestock manure; second, establishment of a history management system for livestock manure transactions; and third, development of a water quality assessment system.