• Title/Summary/Keyword: logistic function

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A Study on the Needs Level for a Demand Estimation Model in Knowledge Administration Activities (지식행정 활동의 수요예측 모형을 위한 요구수준 진단)

  • Kim, Gu
    • Knowledge Management Research
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    • v.6 no.2
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    • pp.23-47
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    • 2005
  • This study is performed the multinomial logistic regression with the officials needs level about a component of knowledge administration for drawing a demand estimation model in the knowledge administration activities. This study is not that an activity and domain of knowledge administration is to apply and to operate uniformly it in public sector, one is suggested an application with a demand diagnose of knowledge administration in order to saw a course of the knowledge administration programs to suit a function and role of public administration. A result of this study is that an activity and domain of the knowledge administration is different from a component of it namely, knowledge creating, knowledge organizing, knowledge sharing and distribution, knowledge utility, and knowledge store. And the officials individual characteristics, administration agency, a kind of business, and a function and role of work are different from demand of knowledge administration. Also, the practical use of KMS (knowledge management system) is not so high in public sector. Accordingly, the tools of knowledge administration will deliberate on a consolidation with the existing system in the device.

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Factors associated with Cognitive Decline in the Elderly in Community (일 지역사회 노인의 인지기능저하 요인)

  • Kwon, Young-Sook;Paek, Kyung-Shin
    • Journal of Digital Convergence
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    • v.12 no.2
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    • pp.587-594
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    • 2014
  • This study was carried out to look into the cognitive function of the elderly in community and investigate the factors affecting their cognitive decline provide preliminary data so as to help develop a program to maintain and promote cognitive function. With 481 senior citizens aged over 65 in J. city, a survey was conducted on their demographic characteristics, health-related characteristics and depression using structured questionnaires from September 1 through 7, 2011. The collected data were analyzed by descriptive statistics, Chi-square test and logistic regression analysis using IBM SPSS Statistics V. 20. As a result of this study, 40.1% of the subjects showed cognitive decline and the factors related to their cognitive decline turned out to be the level of education (p<.001), age (p=.000), depression and exercise (p<.05). Therefore, intervention programs on depression or exercise should be implemented intensively and in particular, various programs and educations should be provided considering individual differences according to the level of education and age.

Prediction of Rear-end Crash Potential using Vehicle Trajectory Data (차량 주행궤적을 이용한 후미추돌 가능성 예측 모형)

  • Kim, Tae-Jin;O, Cheol;Gang, Gyeong-Pyo
    • Journal of Korean Society of Transportation
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    • v.29 no.3
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    • pp.73-82
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    • 2011
  • Recent advancement in traffic surveillance systems has allowed the researchers to obtain more detailed vehicular movement such as individual vehicle trajectory data. Understanding the characteristics of interactions between leading and following vehicles in the traffic flow stream is a backbone for designing and evaluating more sophisticated traffic and vehicle control strategies. This study proposes a methodology for estimating rear-end crash potential, as a probabilistic measure, in real-time based on the analysis of vehicular movements. The methodology presented in this study consists of three components. The first predicts vehicle position and speed every second using a Kalman filtering technique. The second estimates the probability for the vehicle's trajectory to belong to either 'changing lane' or 'going straight'. A binary logistic regression (BLR) is used to model the lane-changing decision of the subject vehicle. The other component calculates crash probability by employing an exponential decay function that uses time-to-collision (TTC) between the subject vehicle and the front vehicle. The result of this study is expected to be adapted in developing traffic control and information systems, in particular, for crash prevention.

Comparing Accuracy of Imputation Methods for Categorical Incomplete Data (범주형 자료의 결측치 추정방법 성능 비교)

  • 신형원;손소영
    • The Korean Journal of Applied Statistics
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    • v.15 no.1
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    • pp.33-43
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    • 2002
  • Various kinds of estimation methods have been developed for imputation of categorical missing data. They include category method, logistic regression, and association rule. In this study, we propose two fusions algorithms based on both neural network and voting scheme that combine the results of individual imputation methods. A Mont-Carlo simulation is used to compare the performance of these methods. Five factors used to simulate the missing data pattern are (1) input-output function, (2) data size, (3) noise of input-output function (4) proportion of missing data, and (5) pattern of missing data. Experimental study results indicate the following: when the data size is small and missing data proportion is large, modal category method, association rule, and neural network based fusion have better performances than the other methods. However, when the data size is small and correlation between input and missing output is strong, logistic regression and neural network barred fusion algorithm appear better than the others. When data size is large with low missing data proportion, a large noise, and strong correlation between input and missing output, neural networks based fusion algorithm turns out to be the best choice.

The Comparative Study of Software Optimal Release Time of Finite NHPP Model Considering Property of Nonlinear Intensity Function (비선형 강도함수 특성을 이용한 유한고장 NHPP모형에 근거한 소프트웨어 최적방출시기 비교 연구)

  • Kim, Kyung-Soo;Kim, Hee-Cheul
    • Journal of Digital Convergence
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    • v.11 no.9
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    • pp.159-166
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    • 2013
  • In this paper, make a study decision problem called an optimal release policies after testing a software system in development phase and transfer it to the user. When correcting or modifying the software, finite failure non-homogeneous Poisson process model, presented and propose release policies of the life distribution, half-logistic property model which used to an area of reliability because of various shape and scale parameter. In this paper, discuss optimal software release policies which minimize a total average software cost of development and maintenance under the constraint of satisfying a software reliability requirement. In a numerical example, the parameters estimation using maximum likelihood estimation of failure time data, make out estimating software optimal release time. Software release time is used as prior information, potential security damages should be reduced.

A Hierarchical Approach for Diagnose of Safety Performance and Factor Identification for Black Spots (Black on Suwon-city) (사고다발지점의 안전성능진단 및 위치별 사고요인분석(수원시를 중심으로))

  • Kim, Suk-Hui;Jang, Jeong-A;Choe, Gi-Ju
    • Journal of Korean Society of Transportation
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    • v.23 no.1
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    • pp.9-20
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    • 2005
  • Accident type and/or factor identification is important in accident reduction planning. The aim of this paper is to apply the hierarchical approach with binomial distribution and logistic regression analysis to find out types and factors, respectively. Based on 2001 Suwon city black spot data, a binomial distribution modeling approach has been applied to diagnose the black spots, with the help of safety performance modeling approach has been applied to diagnose the black spots, with the help of safety performance function. Then, the logistic regression analysis has been employed to identify the critical factors. Some accident remedies are also reviewed in the light of the model outcomes. The proposed research framework sheds light on a different accident related research and can also be successfully applied to similar studies and sites.

Impact of Masticatory Discomfort on Daily Living Difficulties in Korean Elderly with Cognitive Decline

  • Kyung-Yi Do;Chun-Bae Kim;Yeon-Soon Ahn
    • Journal of dental hygiene science
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    • v.23 no.2
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    • pp.142-153
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    • 2023
  • Background: Cognitive impairment has been reported to be closely associated with poor oral health, and the relationship is bidirectional, as older adults with poor oral health and chewing function are at a higher risk of cognitive decline (CD). This cross-sectional study aimed to determine whether masticatory discomfort in Korean elderly increases the risk of daily living difficulty (DLD) related to CD and whether there is a difference in risk according to gender and age. Methods: The data used were obtained from the Korean Community Health Survey (2019). The final analysis included 22,154 people aged 65 years and older who completed the survey and responded to all items on the variables used in the study. Chi-square test, trend test, and complex sample logistic regression were performed for statistical analysis, to clarify the purpose of this study. Results: As masticatory discomfort increased, the elderly's DLD tended to increase (p-for trend, p<0.001). For logistic regression, adjusting for all covariates, participants who reported masticatory discomfort as "discomfort" (adjusted odds ratio [AOR]=2.45, 95% confidence interval [CI]=2.11~3.50) and "severe discomfort" (AOR=2.95, 95% CI=2.49~3.50) had a more than a two-fold increased risk of CD-related DLD compared to participants who reported "no discomfort at all." In age-stratified analyses, elderly men aged 75~84 years and elderly women aged 65~74 years had the highest risk of developing CD-related DLD. Conclusion: Oral care interventions to improve masticatory function in older adults may slow CD and improve CD-related DLD. We hope that this study will raise awareness among caregivers and clinical professionals regarding the importance of oral care for older adults with CD.

Size selectivity of round traps for greenling (Hexagrammos otakii) in the western sea of Korea (원통형 통발에 대한 서해안 쥐노래미 (Hexagrammos otakii)의 망목선택성)

  • 신종근;박해훈
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.39 no.3
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    • pp.174-180
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    • 2003
  • This study investigated the size selectivity of the round traps for greenling (Hexagrammos otakii) in the western sea of Korea. The selection curve for the greenling from the experiments on Oct. 2000 and Ar. 2001 was fitted by Kitahara's method to a polynomial equation and two parameter logistic selection curve. The selectio curve of the latter was more reasonable than that of the former. The equation of selectivity curve obtained using a logistic function with least square method was , s(R)=1/1+exp(-1.1169R+6.4565), where R=1/m, and 1 and m are total length and mesh size, respectively. The size selectivity curve showed that the current regulated mesh size(35mm) in case of the round trap was close to the L50 (37.0mm) of the selection curve for the biological minimum length (21.4cm) of the greenling.

Korea-specified Maximum Expected Utility Model for the Probability of Default (기대효용최대화를 통한 한국형 기업 신용평가 모형)

  • Park, You-Sung;Song, Ji-Hyun;Choi, Bo-Seung
    • The Korean Journal of Applied Statistics
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    • v.20 no.3
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    • pp.573-584
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    • 2007
  • A well estimated probability of default is most important for constructing a good credit scoring process. The maximum expected utility (MEU) model has been suggested as an alternative of the traditional logistic regression model. Because the MEU model has been constructed using financial data arising from North America and European countries, the MEU model may not be suitable to Korean private firms. Thus, we propose a Korea-specific MEU model by estimating the parameters involved in kernel functions. This Korea-specific MEU model is illustrated using 34,057 private firms to show the performance of the MEU model relative to the usual logistic regression model.

Modeling the Multi-Dimensional Phenomenon of Fatiguing by Assessing the Perceived Whole Body Fatigue and Local Muscle Fatigue During Squat Lifting (무릎들기 작업 시 전신피로 감지 수준과 근육 피로도를 활용한 다면적 피로현상 모델링)

  • Ahmad, Imran;Kim, Jung-Yong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.4
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    • pp.1-8
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    • 2018
  • Whole body fatigue detection is an important phenomenon and the factors contributing to whole body fatigue can be controlled if a mathematical model is available for its assessment. This research study aims at developing a model that categorizes whole body exertion into fatigued and non-fatigued states based on physiological and perceived variables. For this purpose, logistic regression was used to categorize the fatigued and non-fatigued subject as dichotomous variable. Normalized mean power frequency of eight muscles from 25 subjects was taken as physiological variable along with the heart rate while Borg scale ratings were taken as perceived variables. The logit function was used to develop the logistic regression model. The coefficients of all the variables were found and significance level was checked. The detection accuracy of the model for fatigued and non-fatigues subjects was 83% and 95% respectively. It was observed that the mean power frequency of anterior deltoid and the Borg scale ratings of upper and lower extremities were significant in predicting the whole body fatigued when evaluated dichotomously (p < 0.05). The findings can help in better understanding of the importance of combined physiological and perceived exertion in designing the rest breaks for workers involved in squat lifting tasks in industrial as well as health sectors.