• Title/Summary/Keyword: statistical assessment

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

  • Jo, Ayeong;Ryu, Jieun;Chung, Hyein;Choi, Yuyoung;Jeon, Seongwoo
    • Journal of Environmental Impact Assessment
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    • v.27 no.5
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    • pp.447-474
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    • 2018
  • The purpose of this study is to build a new dataset of spatially interpolated climate data of South Korea by performing various geo-statistical interpolation techniques for comparison with the LDAPS grid data of KMA. Among 595 observation data in 2017, 80 % of the total points and remaining 117 points were used for spatial mapping and quantification,respectively. IDW, cokriging, and kriging were performed via the ArcGIS10.3.1 software and Python3.6.4, and each result was then divided into three clusters and four watersheds for statistical verification. As a result, cokriging produced the most suitable grid climate data for instantaneous temperature. For 1-hr accumulated precipitation, IDW was most suitable for expressing local rainfall effects.

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

  • 김희섭
    • Journal of the Korean Society for information Management
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    • v.18 no.3
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    • pp.265-284
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    • 2001
  • The aim of this study was to discover the correlation between users cognitive style and their attitude towards evaluating the system. Postgraduate students cognitive styles were defined as Verbaliser/Imager and Wholist/Analytic, and the functionality and ease of learning features of a Web-based OPAC(Online Public Access Catalogue) system were evaluated using a combined evaluation methods: interviews for the preliminary survey, a questionnaire far the central data collection, and a psychometric approach for the judgement of students cognitive style using Ridings CSA(Cognitive Style Assessment) tool. Forty-four postgraduate student volunteers responded and data was analysed using SPSS(Statistical Package for Social Science) for Windows. The statistical analysis of each feature of the evaluation, the correlation between the variables, and the features were explored using Pearsons correlation coefficients(r). In exploring the effects of the cognitive styles of individuals, this study has failed to reveal a significant (P < 0.05) correlations in the interactive Web-based OPACs evaluation. It could be said that the contribution of cognitive styles to evaluating Web-based OPACs is likely to be weaker than that of non-cognitive (or demographic) variables.

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

  • Jo, Gyeol-Ja
    • The Korean Nurse
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    • v.29 no.5
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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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    • v.21 no.2
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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.

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

  • Seo, Young Kyoung;Koh, Jae Sook;Lee, Won Chul
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.2
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    • pp.105-115
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    • 2013
  • In Korea, the human skin tests to evaluate the anti-wrinkles and whitening effect have been accomplished in accordance with the KFDA guideline. Regarding the data of the visual assessment and machinery evaluation of the results for the human skin test, unpaired t-test have been used in order to compare between the test and the control groups and paired t-test for the comparison of effects for before and after. Descriptive statistics such as frequency analyses was used for the questionnaire evaluation data. In many cases of the European and American clinical test centers, the methodology and the statistical analysis were similar to ours. But, the documentation obtained by repeated application from identical individual has high relation. For this reason, it is desirable to apply RM ANCOVA and RM ANOVA to a visual assessment and machinery evaluation. We suggested that RM ANCOVA and RM ANOVA is the new approach to statistical analysis of human test data of functional cosmetics.

Study on Standards of Combustion Stability Assessment of Liquid Rocket Engine Combustion Devices (액체로켓 엔진 연소장치의 연소 안정성 평가 기준에 대한 연구)

  • Seo, Seong-Hyeon;Lee, Kwang-Jin;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.6
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    • pp.34-40
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    • 2009
  • The present study describes the methods and standards for the combustion stability assessment of a thrust chamber and a gas generator as parts of a liquid rocket engine. The first method uses a statistical approach through typical static combustion tests and the second one a dynamic assessment identifying decaying characteristics of pressure fluctuations excited by a pulse generating device. Based on accumulated test results, it is concluded that the maximal values for combustion stability are 3% of a chamber static pressure with a Root-Mean-Square value of pressure fluctuations, and 10 msec with a decay time.

Vulnerability assessment of upland public groundwater wells against climate change

  • Shin, Hyung Jin;Lee, Jae Young;Jo, Sung Mun;Cha, Sang Sun;Park, Chan Gi
    • Korean Journal of Agricultural Science
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    • v.47 no.3
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    • pp.577-596
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    • 2020
  • Drought is a natural disaster that directly affects agriculture, which has a great impact on the global agricultural production system and yield. The lack of water storage in most parts of the country due to the lack of precipitation has caused a great increase in social interest in drought due to the dryness of rice fields and crops. As the drought period increases and the drought intensity becomes stronger, it is believed that drought damage to crops will continue; thus, it is necessary to understand the vulnerability to irrigation performance and the ability of irrigation facilities. Therefore, this study conducted a vulnerability assessment of irrigation facilities (public Groundwater well) in cities across the country. The survey was conducted using statistical data from 2007 to 2016, and the vulnerability score was calculated according to the vulnerability evaluation procedure for drought in the irrigation facilities (public groundwater wells). Among 157 regions, 136 areas were very vulnerable; 14 areas were vulnerable; 3 areas were normal; 4 areas were good, and 0 areas were excellent. The vulnerability assessment can be used as basic data for the development or maintenance of field irrigation facilities in the future by understanding the vulnerability of irrigation facilities.

Time-dependent analysis of cable trusses -Part II. Simulation-based reliability assessment

  • Kmet, S.;Tomko, M.;J., Brda
    • Structural Engineering and Mechanics
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    • v.38 no.2
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    • pp.171-193
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    • 2011
  • One of the possible alternatives of simulation-based time-dependent reliability assessment of pre-stressed biconcave and biconvex cable trusses, the Monte Carlo method, is applied in this paper. The influence of an excessive deflection of cable truss (caused by creep of cables and rheologic changes) on its time-dependent serviceability is investigated. Attention is given to the definition of the basic random variables and their statistical functions (basic, mutually dependent random variables such as the pre-stressing forces of the bottom and top cable, structural geometry, the Young's modulus of elasticity of the cables, and the independent variables, such as permanent load, wind, snow and thermal actions). Then, the determination of the response of the cable truss to the loading effects, and the definition of the limiting values considering serviceability of the structure are performed. The potential of the method, using direct Monte Carlo technique for simulation-based time-dependent reliability assessment as a powerful tool, is emphasized. Results obtained by the First order reliability method (FORM) are compared with those obtained by the Monte Carlo simulation technique.

Risk Assessment and Pharmacogenetics in Molecular and Genomic Epidemiology

  • Park, Sue-K.;Choi, Ji-Yeob
    • Journal of Preventive Medicine and Public Health
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    • v.42 no.6
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    • pp.371-376
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    • 2009
  • In this article, we reviewed the literature on risk assessment (RA) models with and without molecular genomic markers and the current utility of the markers in the pharmacogenetic field. Epidemiological risk assessment is applied using statistical models and equations established from current scientific knowledge of risk and disease. Several papers have reported that traditional RA tools have significant limitations in decision-making in management strategies for individuals as predictions of diseases and disease progression are inaccurate. Recently, the model added information on the genetic susceptibility factors that are expected to be most responsible for differences in individual risk. On the continuum of health care, from diagnosis to treatment, pharmacogenetics has been developed based on the accumulated knowledge of human genomic variation involving drug distribution and metabolism and the target of action, which has the potential to facilitate personalized medicine that can avoid therapeutic failure and serious side effects. There are many challenges for the applicability of genomic information in a clinical setting. Current uses of genetic markers for managing drug therapy and issues in the development of a valid biomarker in pharmacogenetics are discussed.

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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    • v.69 no.3
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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.