• Title/Summary/Keyword: weighting factors

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Development of Integrity Evaluation Techniques for Concrete Structures (콘크리트 구조물의 건전성 평가 기법 개발)

  • 정연주;김도겸;이장화;조명석;송영철
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.623-626
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    • 1999
  • Structural integrity in concrete structures are affected by materialistic and environmental factors. Therefore, to develop a objective integrity evaluation method is extremely difficult. In this study, preliminary integrity evaluation method for concrete structures was proposed by conducting by visual and detailed inspection for in-situ conditions based on the weighting factors for structural significance and integrity degrading factors of each element constituting concrete structures.

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Ground Subsidence Risk Ratings for Pre-excavation (굴착 전 지반함몰 예측을 위한 위험등급 분류)

  • Ihm, Myeong-Hyek;Shin, Sang-Sik;Kim, Woo-Seok;Kim, Hak Joon
    • The Journal of Engineering Geology
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    • v.28 no.4
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    • pp.553-563
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    • 2018
  • The recent increase of ground subsidence in Korea requires the development of technology for predicting the possibility of ground subsidence. Eighteen parameters affecting the ground subsidence for pre-excavation are classified into 6 categories considering ground types, groundwater, and external factors. Eighteen parameters consists of a table which gives ground subsidence risk ratings for pre-excavation(GSRp). Certain scores are given to these parameters after they are divided into several classes considering the importance and the credibility of parameters and the engineering judgements of the authors. Because of the difference of ground subsidence factors depending on the ground and field conditions, weighting factors for the individual factor and for the each category are multiplied. Weighting factors are calculated from citation frequencies of influencing factors. Ground subsidence risk ratings for pre-excavation can be quantified by considering the individual score of each parameter and weighting factors for the individual factor and for the each category. The suggested GSRp tables obtained from this study are expected to be used by engineers for the estimation of ground subsidence risk ratings for pre-excavation sites.

The lnfluence of Weighting Value derived by the Regression Equation on the Result of Vulnerability Assessment (회귀식에 의해 도출된 가중치가 취약성 평가에 미치는 영향)

  • Yoo, Somin;Lee, Woo-kyun;Chae, Yeo-ra;Kwak, Hanbin;Kim, Moon-Il;Jung, Raesun
    • Journal of Climate Change Research
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    • v.4 no.4
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    • pp.331-348
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    • 2013
  • The frequency and intensity of abnormal climate caused by climate change is increasing in Korea. Also, the amount of damage from disaster is increasing rapidly. The research on vulnerability assessment analyzes environmentally, socially and economically vulnerable indicators and is ongoing to reduce the intensity of damage and establish adaptation policies for climate change. Therefore, in this study, we assessed vulnerability using weighting value derived by the regression equation. There are 3 evaluation items : vulnerability assessment for farmland erosion to flood, vulnerability assessment for health to heat wave, vulnerability assessment for forest fire to drought. For this study, indicators for each sectors were selected and spatial data for each sectors were established using GIS program. Results showed that vulnerability to heat wave was more affected by climate factors. On the other hand, vulnerability to flood and drought was more affected by social-economic factors. Then, to analysis efficiency of the regression analysis, vulnerability result was compared between the existing vulnerability research with no weighting applied and the vulnerability research with the influence of weighting value derived by the regression. This study showed that the regression analysis is efficient to provide practical and feasible alternatives in terms of planning climate change adaptation policies and it is expected to be utilized for vulnerability assessment in the future.

Regression model for the preparation of calibration curve in the quantitative LC-MS/MS analysis of urinary methamphetamine, amphetamine and 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid using R (소변 중 메트암페타민, 암페타민 및 대마 대사체 LC-MS/MS 정량분석에서 검량선 작성을 위한 R을 활용한 회귀모델 선택)

  • Kim, Jin Young;Shin, Dong Won
    • Analytical Science and Technology
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    • v.34 no.6
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    • pp.241-250
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    • 2021
  • Calibration curves are essential in quantitative methods and for improving the accuracy of analyte measurements in biological samples. In this study, a statistical analysis model built in the R language (The R Foundation for Statistical Computing) was used to identify a set of weighting factors and regression models based on a stepwise selection criteria. An LC-MS/MS method was used to detect the presence of urinary methamphetamine, amphetamine, and 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol in a sample set. Weighting factors for the calibration curves were derived by calculating the heteroscedasticity of the measurements, where the presence of heteroscedasticity was determined via variance tests. The optimal regression model and weighting factor were chosen according to the sum of the absolute percentage relative error. Subsequently, the order of the regression model was calculated using a partial variance test. The proposed statistical analysis tool facilitated selection of the optimal calibration model and detection of methamphetamine, amphetamine, and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in urine. Thus, this study for the selection of weighting and the use of a complex regression equation may provide insights for linear and quadratic regressions in analytical and bioanalytical measurements.

Assessment of Landslide Causal Factors Using ANN Method (ANN 기법을 이용한 사면 붕괴인자 평가)

  • Song, Young-Karb;Jung, Min-Su;Oh, Jeong-Rim;Cha, A-Reum
    • Journal of the Korean Geotechnical Society
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    • v.28 no.10
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    • pp.89-96
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    • 2012
  • In this study landslide causal factors which are considered to have the same effect in assessment techniques are categorized and their impact on landslides is analyzed to acquire reasonable weighting factors in the landslide hazard. Results are compared to those of the Assessment Chart developed by National Institute for Disaster Prevention (NIDP) and the adequacy and proper portion for landslide causal factors are considered. The Artificial Neural Network (ANN) method applied to 28 landslide areas is incorporated to evaluate the reasonable rating. Results show that the following items in the Chart are necessary to modify their portions in order to implement the precise assessment results: 1) Estimated damage; 2) Tension crack; 3) Existence of valley.

Analysis of Installation Status and Application of GIS for Preliminary Risk Assessment of Underground Storage Tanks in Chuncheon City (춘천시의 지하 저장 탱크의 예비적 위해성 평가를 위한 설치 현황 분석 및 지리정보시스템의 적용)

  • Kim, Joon-Hyun;Han, Young-Han;Lee, Jong-Chun;Kwon, Young-Sung;Lee, Kwang-Yeon
    • Journal of Industrial Technology
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    • v.22 no.A
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    • pp.127-135
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    • 2002
  • In this study, the preliminary risk assessment for the underground storage tanks(UST) in Chunchon city was implemented using the geographical information system(GIS). The estimation variables, such as the installation year, storage capacity, the distances from streams, and from groundwater pumping wells, were selected to estimate the relative risk levels. The weighting factors were given to all the estimation variables. Cumulative scores were induced by the combination of all the scores of the corresponding variables using the buffering technique and the overlay analysis in ArcView. Using the these process, the relative risk level of each UST was estimated. Some sites in this study are simplified and reduced because the number of useable data are limited or too enormous. Thus the selection of the comprehensive estimation variables and the proper weighting values are required for the future study. The methodology in this study could be served not only for the preliminary risk assessment of UST but also for the selection of the proper location of new and old UST. And, it can be used for the effective management system of UST.

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Design of Acceptance Control Charts According to the Process Independence, Data Weighting Scheme, Subgrouping, and Use of Charts (프로세스의 독립성, 데이터 가중치 체계, 부분군 형성과 관리도 용도에 따른 합격판정 관리도의 설계)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.12 no.3
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    • pp.257-262
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    • 2010
  • The study investigates the various Acceptance Control Charts (ACCs) based on the factors that include process independence, data weighting scheme, subgrouping, and use of control charts. USL - LSL > $6{\sigma}$ that used in the good condition processes in the ACCs are designed by considering user's perspective, producer's perspective and both perspectives. ACCs developed from the research is efficiently applied by using the simple control limit unified with APL (Acceptable Process Level), RLP (Rejectable Process Level), Type I Error $\alpha$, and Type II Error $\beta$. Sampling interval of subgroup examines i.i.d. (Identically and Independent Distributed) or auto-correlated processes. Three types of weight schemes according to the reliability of data include Shewhart, Moving Average(MA) and Exponentially Weighted Moving Average (EWMA) which are considered when designing ACCs. Two types of control charts by the purpose of improvement are also presented. Overall, $\alpha$, $\beta$ and APL for nonconforming proportion and RPL of claim proportion can be designed by practioners who emphasize productivity and claim defense cost.

A Study on the Weighting of Open Access Maturity Stages of Domestic Academic Organizations Using AHP: Focusing on Korea Institute of Science and Technology Information (AHP를 활용한 국내 학술단체 오픈액세스 성숙단계 가중치 부여 연구 - 한국과학기술정보연구원을 중심으로 -)

  • Jin Ho Park
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.34 no.2
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    • pp.115-136
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    • 2023
  • The purpose of this study is to establish a weighting system for the diagnostic criteria of the KISTI Open Access Maturity Model. The maturity model consists of three dimensions, 12 sub-dimensions, and 28 measurement questions. Weighting was performed for the three dimensions and 12 sub-dimensions to determine their relative importance. The results showed that 'Institutionalization of OA' (48%) was the most important factor in the three dimensions. Among the sub-factors of "institutionalizing OA," "enacting and revising relevant regulations" (64%) was important, and "financing" (39%) was important for "OA sustainability. Submission and review (23%) and author rights (22%) were identified as important elements of "journal openness".

Study of Determination in Measurement System for Safely Managing Debris-Flow (안전한 토석류 관리를 위한 계측기 선정에 관한 연구)

  • Min, Dae-Hong;Yoon, Hyung-Koo
    • Journal of the Korean Society of Safety
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    • v.32 no.3
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    • pp.41-47
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    • 2017
  • Recent studies have shown that there are various systems which can be used to monitor hazardous area in a debris flow location, but lack of methodological research on the exact location where each instrument should be installed has hindered the success of this systems. The objective of this study is to suggest the measurement system for monitoring debris-flow and propose the effective method to determine location of measurement system. Previously studied, from 1991 to 2015, were referred and the applied ratio of every instrument was investigated. The measurement information was divided into 8 categories including rainfall, debris-flow velocity, displacement, fluid pore pressure, ground vibration, image processing, impact force and peak flow depth. The result of this study revealed that the most applied instruments to be rain gauge and geophone for measuring average rainfall and ground vibration respectively. The Analytic Hierarchical Process (AHP) method was selected to determine installation location of instrument and the weighting factors were estimated through fine content, soil thickness, porosity, shear strength, elastic modulus, hydraulic conductivity and saturation. The soil thickness shows highest weights and the fine content relatively demonstrates lowest weights. The score of each position can be calculated through the weighting factors and the lowest score position can be judged as the weak point. The weak point denotes the easily affecting area and thus, the point is suitable for installing the measurement system. This study suggests a better method for safely managing the debris-flow through a precise location for installing measurement system.