• Title/Summary/Keyword: systematic factor

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On the Development of Risk Factor Map for Accident Analysis using Textmining and Self-Organizing Map(SOM) Algorithms (재해분석을 위한 텍스트마이닝과 SOM 기반 위험요인지도 개발)

  • Kang, Sungsik;Suh, Yongyoon
    • Journal of the Korean Society of Safety
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    • v.33 no.6
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    • pp.77-84
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    • 2018
  • Report documents of industrial and occupational accidents have continuously been accumulated in private and public institutes. Amongst others, information on narrative-texts of accidents such as accident processes and risk factors contained in disaster report documents is gaining the useful value for accident analysis. Despite this increasingly potential value of analysis of text information, scientific and algorithmic text analytics for safety management has not been carried out yet. Thus, this study aims to develop data processing and visualization techniques that provide a systematic and structural view of text information contained in a disaster report document so that safety managers can effectively analyze accident risk factors. To this end, the risk factor map using text mining and self-organizing map is developed. Text mining is firstly used to extract risk keywords from disaster report documents and then, the Self-Organizing Map (SOM) algorithm is conducted to visualize the risk factor map based on the similarity of disaster report documents. As a result, it is expected that fruitful text information buried in a myriad of disaster report documents is analyzed, providing risk factors to safety managers.

Turnover intention among dental hygienists in Korea: a systematic review and meta-analysis (한국 임상치과위생사의 이직의도 관련 요인에 대한 체계적 문헌고찰 및 메타분석)

  • Lee, Da-Som;Hong, Hae-Kyung;Han, Gyeong-Soon
    • Journal of Korean society of Dental Hygiene
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    • v.22 no.4
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    • pp.259-272
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    • 2022
  • Objectives: To identify the factors influencing the turnover intention of registered South Korean dental hygienists and analyze the effect sizes. Methods: Overall, 54 studies based on criteria of PICO from 1 January 2000 to 11 January 2022 were extracted. The factors related to turnover intention were applied to the ecological system theory and categorized. Subsequently, the effect size of the correlations was comprehensively meta-analyzed by dividing it into protective and risk factors depending on the negative or positive correlation direction. Results: For the overall effect size, the protective factor (ESr=-0.458) was higher than the risk factor (ESr=0.352). In the protective factors, organizational commitment and perceived organizational support belonging to the microsystem yielded the largest effect size. Furthermore, as for risk factors, burnout, job stress, work harassment, role conflict, and emotional labor belonging to the microsystem showed a moderate effect size. Conclusions: Factors belonging to the microsystem demonstrated a large effect size in both protection and risk factors for dental hygienists' turnover intention. Additionally, the factor showing the largest effect size was protective factor categorized into a microsystem.

The Effect of Laser Geometry and Material Parameters on the Single Mode Gain Difference in Quarter Wavelength Shifted DFB Laser above Threshold Current (문턱전류이상에서 구조 및 재료 변수들이 $\lambda$/4위상천이 DFB 레이저의 단일모드 이득차에 미치는 영향)

  • 이홍석;김홍국;김부균;이병호
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.3
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    • pp.75-84
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    • 1999
  • Systematic studies for the effect of the linewidth enhancement factor, the confinement factor, the internal loss and the cavity length on the single mode gain difference and the frequency detuning are performed for $\lambda$/4 phase shifted DFB lasers above threshold. The above threshold characteristics are mainly determined by the linewidth enhancement factor, not by the confinement factor or the parameter defined by the product of the linewidth enhancement factor and the confinement factor. The normalized internal loss defined by the product of the internal loss and the cavity length mainly determines the above threshold characteristics compared to that of the internal loss or the cavity length alone. The effect of the cavity length on threshold characteristics is larger than that of the internal loss in the case of the same normalized internal loss. The above threshold characteristics of quantum well lasers are more resistant to the variations of the confinement factor and the normalized internal loss than those of bulk lasers due to the small linewidth enhancement factor.

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The Extraction of Soil Erosion Model Factors Using GSIS Spatial Analysis (GSIS 공간분석을 활용한 토양침식모형의 입력인자 추출에 관한 연구)

  • 이환주;김환기
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.1
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    • pp.27-37
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    • 2001
  • Soil erosion by outflow of water or rainfall has caused many environmental problems as declining agricultural productivity, damaging pasture and preventing flow of water. As the interest in environment is increasing lately, soil erosion is considered as a serious problem, whereas the systematic regulation and analysis for that have not established yet. This research shows the method of extracting factor entered model which expects soil erosion by GSIS. There are several erosion model such as ANSWER, WEPP, RUSLE. The research used RUSLE erosion model which could expect general soil erosion connected easily with GSIS data. RUSLE's input factors are composed of rainfall runoff factor(R). soil erodibility factor(K), slope length factor(L), slope steepness factor(S), cover management factor(C) and support practice factor(P). The general equation used to extract L, S factor on the RUSLE to be oriented for agricultural area has some limitation to apply whole watershed. So, on this study we used a revised empirical equation applicable to the watershed by grid on the GSIS. Also, we analyzed RUSLE factors by watershed being analyzed with watershed extraction algorithm. Then we could calculate the minimum, maximum. mean and standard deviation of RUSLE factors by watershed.

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A Study on Characteristics for a Contract Power Conversion Factor and Analysis of a Maximum Utilization Factor of Transformer in Industrial Customers (산업용전력사용고객의 변압기최대이용률과 계약전력환산율에 관한 연구)

  • Kim, Se-Dong;Yoo, Sang-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.6
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    • pp.44-49
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    • 2008
  • Contract power conversion factor which is applied to estimate contract power of industrial customers is an important standard to caculate transformer capacity. This paper shows a reasonable contract power conversion factor, that was made by the systematic and statistical way considering actual conditions, such as investigated contact power and peak power for the last 5 years of each customer for 349 industrial customers as to AMR. In this dissertation, it is necessary to analyze the key features and general trend from the investigated data. It made an analysis of the feature parameters, such as average, standard deviation, median, maximum, minimun and thus it was carried by the linear and nonlinear regression analysis. Therefore, this paper compared characteristics for a contract power conversion factor which is a lied to calculate contract power with characteristics for a regression model for customers which maximum utilization factor of transformer is more than 60(%).

A Study on Characteristics for a Contract Power Conversion Factor and Analysis of a Maximum Utilization Factor of Transformer in General Customers (일반용전력사용고객의 변압기최대이용률과 계약전력환산율 기준과의 비교 특성 연구)

  • Kim, Se-Dong;Wang, Yong-Peel
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.5
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    • pp.80-85
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    • 2008
  • Contract power conversion factor which is applied to estimate contract power of general customers is an important standard to caculate transformer capacity. This paper shows a reasonable contract power conversion factor, that was made by the systematic and statistical way considering actual conditions, such as investigated contract power and peak power for the last 5 years of each customer for 461 general customers as to AMR. In this dissertation, it is necessary to analyze the key features and general trend from the investigated data It made an analysis of the feature parameters, such as average, standard deviation, median, maximum, minimun and thus it was carried by the linear and nonlinear regression analysis. Therefore, this paper compared characteristics for a contract power conversion factor which is applied to estimate contract power with characteristics for a regression model for customers which maximum utilization factor of transformer is more than 60[%].

Estimation and Variance Estimation for the U.S. Consumer Expenditures Surveys Redesign Research

  • Kim, Jong-Ik
    • Journal of the Korean Statistical Society
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    • v.12 no.1
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    • pp.36-45
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    • 1983
  • After every decennial census in the U.S., national surveys such as the Consumer Expenditures surveys are redesigned. The redesigned samples will be multi-stage systematic samples. Many sampling schemes have been proposed for comparison which requires the estimation and variance estiamtion formula. This paper deals with the surveys redesign research which concerns the sample design within the Primary Sampling Unit (PSU). In constructing the estimators it deals with the problem of which first stage inflation factor to use. The expected value of the proposed estimators is also derived.

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Control of Platelet Rolling and Adhesion

  • Moskowitz, Samuel E.
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.77.1-77
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    • 2002
  • Platelets arrest bleeding and repair damaged blood vessels. The purpose of this paper is to formulate a mathematical model for the control of platelet adhesion within the vasculature consistent with experimental findings, particularly those of Frenette, Ruggeri , Savage, Yuan, Lawrence and Springer. In addition to providing some, albeit rudimentary, insight into the behavior of platelets, a numerical simulation of this theoretical model may be useful in a systematic study of pathological cases. Glycoprotein receptor complex (GPIb/V/IX), found on the platelet surface membrane, binds to the adhesive protein and ligand von Willebrand factor (vWf), located within the sub-endothelium. The binding...

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Robust Controller Design by $\textrm{H}_\infty$ Method for a Launch Vehicle ($\textrm{H}_\infty$ 기법에 의한 발사체의 견실한 제어기 설계)

  • 이군석;권오규
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.463-468
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    • 1992
  • In this paper, discrete-time H$_{\infty}$ controller design in .delta.- domaion using Normalized Coprime Factor plant description is proposed and the loop-shaping method developed by Mcfalane[2], which is known to be very simple and systematic method, is adopted here in H$_{\infty}$ controller design. In particular, we show that .delta.- H$_{\infty}$ controller proposed here is a unified form for the continuous and discrete-time cases.es.

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Building Identity and Strategic Scenarios for Railway Culture Design (철도문화디자인의 정체성 구현과 전략 시나리오 구축)

  • 한석우;진미자
    • Journal of the Korean Society for Railway
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    • v.5 no.4
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    • pp.201-208
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    • 2002
  • This study suggests a new paradigm to build the identity of railway culture design, since it plays a critical role in enhancing competitiveness of culture and design. It is considered to be a valuable factor to improve users' satisfaction and to have a new effect on the railway industry. This study is focused on systematic study on the culture & design and competitiveness for railway industry, that emphasizing on making necessary strategic scenarios accordingly. Consequently, it is going to make higher added values to secure a footing and advanced images of railway industry.