• Title/Summary/Keyword: logistic function

Search Result 437, Processing Time 0.023 seconds

Temperature Response and Prediction Model of Leaf Appearance Rate in Rice (벼의 생육온도에 따른 출엽양상과 출엽속도 추정모델)

  • 이충근;이변우;윤영환;신진철
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.46 no.3
    • /
    • pp.202-208
    • /
    • 2001
  • Under the constant daylength of 13 hours and growth temperatures of 15$^{\circ}C$ to 27$^{\circ}C$, the final number of loaves (FNL) on the main culm was constant as 15 regardless of temperature in rice variety 'Kwanganbyeo'. Leaf appearance rate (LAR) increased with rising temperature and decreased with phenological development. Threshold temperature (T$_{o}$) was not constant across growth stages, but increased with phenological development. Effective accumulated temperature (EAT), which is calculated by the summation of values subtracting T0 from daily mean temperature, is closely related with number of leaves appeared (LA). LA was fitted to bilinear, quadratic, power and logistic function of EAT. Among the functions, logistic function had the best fitness of which coefficient of determination was $R^2$=0.995. Therefore, LAR prediction model was established by differentiating this function in terms of time: (equation omitted). where dL/dt is LAR, T$_1$ is daily mean temperature, L is the number of leaves appeared, and a, b, and c are constants that were estimated as 41.8, 1098.38, and -0.9273, respectively. When predictions of LA were made by LAR prediction model using data independent of model establishment, the observed and predicted LA showed good agreement of $R^2$$\geq$0.99.

  • PDF

Positive and Negative Influence of Social Network on Self Rated Health and its Gendered Pattern (사회적 관계망의 긍정적, 부정적 기능이 성별 주관적 건강에 미치는 영향)

  • Park, Su-San;Cho, Sung-Il;Jang, Soong-Nang
    • Korean Journal of Health Education and Promotion
    • /
    • v.28 no.4
    • /
    • pp.39-49
    • /
    • 2011
  • Objectives: This study was to examine the association between structural and functional characteristics of social network and self-rated health in middle-aged Korea population. We also explored gender difference in the relationship between social network and health. Methods: Data were collected from individuals aged 40-69 years old participating in the 2005 survey for the Korean Genome & Epidemiology Study. We examined the association between social network, social support, social conflict and self-rated health using multiple logistic regression analysis stratified by gender. Results: The extent and contact frequency of close people, and social participations were associated by not only the positive function but also the negative function of social network. Both the positive and negative functions of social network affected self-rated health. The relationship between the function of social network and health showed a gender difference: only positive function was significantly associated with health in men while only negative function had significant relationship with health in women. Conclusions: Social support and social conflict affected the health in both genders through different ways. The ambivalent effect of social network on health should be explored further.

The relationship between dental prosthesis status, prosthesis need and mastication function in the Korean elderly population - The 5th Korea National Health and Nutrition Examination Survey(2010-2012)- (한국 노인의 치과보철물 상태 및 필요도와 저작기능의 관련성 연구 -제5기 국민건강영양조사자료 분석(2010-2012)-)

  • Choi, Mi-Sook;Lee, Jong-Hwa;Yun, Hyun-Kyung
    • Journal of Korean society of Dental Hygiene
    • /
    • v.14 no.3
    • /
    • pp.293-302
    • /
    • 2014
  • Objectives : The objective of this study was to investigate the relationship between the status and necessity of dental prosthesis and mastication function in the Korean elderly. Methods : This study investigated 4,557 elderly people aged over 65 in the 5th Korea National Health and Nutrition Examination Survey(2010-2012). Frequency analysis, ${\chi}^2$ test, and logistic regression analysis were used. Results : Those aged over 75 complained of greater discomfort in mastication function than those from 65 to 74, and it was statistically significant(p<0.001). Mastication discomfort was not so significant in those with higher education and higher income(p<0.001). Those who did not use prosthesis tended to have better mastication function(p<0.001). Denture users complained of mastication discomfort when they used it(p<0.001). Conclusions : This study verified the relationship between the discomfort in mastication and related factors, and will provide the basic data for the access to dental clinic services.

Factors Influencing Participation in National Health Screening Program among Korean Older Adults by Cognitive Function Level

  • Han, Song Yi;Ko, Young
    • Research in Community and Public Health Nursing
    • /
    • v.30 no.4
    • /
    • pp.508-517
    • /
    • 2019
  • Purpose: The aim of this study was to identify the participation rate of the National Health Screening Program (NHSP) and its influencing factors by cognitive function level in Korean older adults. Methods: This study was a secondary analysis using data from the survey of the Korean Longitudinal Study of Aging in 2016. The data were analyzed using 𝑥2 test and multiple logistic regression. Results: The participation rates of the NHSP in the mild cognitive impairment group (79.6%) and the suspected dementia group (58.0%) were lower than the normal cognitive function group (88.1%). The factors influencing NHSP varied by cognitive function level. Especially, in the suspected dementia group, higher participation rates of the NHSP were associated with living in rural areas, enrollment in private health insurance, no depressive symptoms, participation in social activities, and no living with children. Depression and participation in social activities influenced participation in NHSP in all groups. Conclusion: This study suggests that interventions differentiated by cognitive function level are important for increasing the participation in the health screening.

Factors Related to Cognitive Function Decline by Socio-demographic and Health-related Characteristics : Based on Korean Longitudinal Study of Ageing(KLoSA) Panel Data (인구사회학적 요인 및 건강관련 특성에 따른 인지기능저하 관련 요인 연구 -고령화연구패널 조사 자료를 이용하여-)

  • Kim, Kyeong-Na;Lee, Hyo-Young;Kim, Soo-Jeong
    • The Korean Journal of Health Service Management
    • /
    • v.14 no.1
    • /
    • pp.137-146
    • /
    • 2020
  • Objectives: The aim of this study was to investigate cognitive function decline by socio-demographic and health-related characteristics (health behaviors and health status) using 5th Korean Longitudinal Study of Aging panel data. Methods: The subjects were 4,440 community-dwelling people aged over 57 years. The data were analyzed with descriptive statistics, frequency analysis, χ2-test, and binary logistic regression analysis using SPSS ver. 25.0. Results: The findings revealed that socio-demographic characteristics (gender, age, area of residence, educational level, marital status, number of children, number of grand-children) and health-related characteristics (smoking, drinking, regular exercise, weight category by body mass index, hypertension and diabetes mellitus) were factors that influenced cognitive function decline (p<.05). Conclusions: Cognitive function decline was closely related to health behaviors and disease types. Future studies must examine related constructs to accurately determine these relationships among various populations. The present study could be used as a tool for the development and implementation of health promotion and prevention strategies.

Long-term Projection of Nuclear Power Capacity -Trend Analysis Using Logistic Function- (장기 원자력 발전 설비용량 전망 -로지스틱함수를 이용한 추세분석-)

  • 임채영;최영명
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
    • /
    • 1998.05a
    • /
    • pp.199-204
    • /
    • 1998
  • 최근 화석연료의 과다한 사용으로 인한 온실효과 등 지구환경문제가 대두되면서 원자력은 온실가스를 배출하지 않는 에너지원으로서 다시 조망을 받고 있다. 특히 부존 에너지자원이 부족하고 전력의 수요가 급증하고 있는 우리의 사정을 고려한다면 원자력은 향후 수십년간 주요 발전원으로 상당한 역할을 수행할 것으로 기대된다. (중략)

  • PDF

ESTIMATION AND SENSITIVITY OF GOMPERTZ PARAMETERS WITH MORTALITY DECELERATION RATE

  • PITCHAIMANI M.
    • Journal of applied mathematics & informatics
    • /
    • v.18 no.1_2
    • /
    • pp.311-320
    • /
    • 2005
  • Studies in the evolutionary biology of aging require good estimates of the age-dependent mortality rate coefficient (one of the Gompertz parameters). In this paper we introduce an alternative algorithm for estimating this parameter. And we discuss the sensitivity of the estimates to changes in the other model parameters.

A Survey on the Safety Management in Korean Logistics Industry (한국 물류 산업에서 안전관리에 관한 연구 문헌 조사)

  • Yang, Byoung-Hak
    • Journal of the Korea Safety Management & Science
    • /
    • v.9 no.5
    • /
    • pp.27-36
    • /
    • 2007
  • Logistics has been recognized as a growing industry in Korea. Accidents in Korean logistics industry are listed up in this paper. As accidents in Korean Logistic industry increasing rapidly, lots of researches on the safety management in logistics industry are published. We surveyed those Korean research papers including supply chain management. Research papers are classified by logistics function and logistics area. Some logistics area still have not been researched on safety management.

Classification via principal differential analysis

  • Jang, Eunseong;Lim, Yaeji
    • Communications for Statistical Applications and Methods
    • /
    • v.28 no.2
    • /
    • pp.135-150
    • /
    • 2021
  • We propose principal differential analysis based classification methods. Computations of squared multiple correlation function (RSQ) and principal differential analysis (PDA) scores are reviewed; in addition, we combine principal differential analysis results with the logistic regression for binary classification. In the numerical study, we compare the principal differential analysis based classification methods with functional principal component analysis based classification. Various scenarios are considered in a simulation study, and principal differential analysis based classification methods classify the functional data well. Gene expression data is considered for real data analysis. We observe that the PDA score based method also performs well.

Optical encryption of multiple images using amplitude mask and 2D chaos function (진폭 마스크와 2D 카오스 함수를 이용한 다중 이미지 광학 암호화)

  • Kim, Hwal;Jeon, Sungbin;Kim, Do-Hyung;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
    • /
    • v.10 no.2
    • /
    • pp.50-54
    • /
    • 2014
  • Object image using DRPE(Double Random Phase Encryption) in 4f system is encrypted by space-division method using amplitude mask. However, this method has the weakness for the case of having partial data of amplitude mask which can access the original image. To improve the security, we propose the method using the 2-dimension logistic chaos function which shuffles the encrypted data. It is shown in simulation results that the proposed method is highly sensitive to chaos function parameters. To properly decrypt from shuffled encryption data, below 1e-5 % errors of each parameter should be required. Thus compared with conventional method the proposed shows the higher security level.