• Title/Summary/Keyword: Model Fitness

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Caenorhabditis elegans as a Biological Model for Multilevel Biomarker Analysis in Environmental Toxicology and Risk Assessment

  • Choi, Jin-Hee
    • Toxicological Research
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    • v.24 no.4
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    • pp.235-243
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    • 2008
  • While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.

A Study On Causal Relationship between Exchange Rate and Economic Growth in Korea (한국의 환율과 경제성장과의 인과관계)

  • Choi, Bong-Ho
    • International Commerce and Information Review
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    • v.10 no.1
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    • pp.329-347
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    • 2008
  • The purpose of this study is to examine the causal relationship between the exchange rate and economic growth, and to induce policy implications. In order to test whether time series data is stationary and the model is fitness or not, we put in operation unit root test, cointegration test. And we apply Granger causality based on an error correction model. The results indicate that uni-dierctional causality between exchange rate and economic growth is detected. Exchange rate impacts on economic growth, but economic growth don't impact on exchange rate. The analysis of impulse reaction function shows that the impulse of exchange rate impacts on Korean economic growth in negative direction. We can infer policy suggestion as follows: The fluctuation of exchange rate much affects economic growth, thus we must make a stable policy of exchange rate to continue economic growth.

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STARSPOT MODEL OF RS CVn TYPE BINARY SZ PSC (RS CVn형 쌍성 SZ Psc의 흑점 모델)

  • 강영운
    • Journal of Astronomy and Space Sciences
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    • v.17 no.2
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    • pp.189-198
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    • 2000
  • The emission lines of the ultraviolet region and the light curves of the optical region have been analyzed to investigate the distorted light curves of SZ Psc. The Mg II emission lines of the IUE spectra confirmed that the chromospheric activity of SZ Psc occurs on the K1 IV star. The distorted light curves in the optical region have been analyzed by the spot model where the spots are on the K1 IV star as the result of the chromospheric activity. The complete photometric solution could be deduced for SZ Psc by the good fitness with the spot model.

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Analysis on the Economic Effects of Calibration for Measurement Instrument in Korean Industry (우리나라 산업(産業)의 측정기기에 대한 교정검사실시효과분석(較正檢査實施效果分析))

  • Kim, Dong-Jin;Choe, Jong-Hu;An, Ung-Hwan
    • Journal of Korean Society for Quality Management
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    • v.19 no.1
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    • pp.83-94
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    • 1991
  • The purpose of this study is to analyze the economic efficiency of the investment for calibrating measurement instruments in manufacturing industries, and to propose the administration scheme of measurement instruments. To investigate the efficieny of calibration, we estimate a multiple regression model composed of variables - product inferiority-rate, calibration rate, etc-, and verify fitness of the model. According to the statistical analysis by LOGIT method, a forecasting model of product inferiority-rate with calibration-related variables is proposed, and its validity is investigated.

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Well-being Lifestyle Measurement Development (웰빙 라이프스타일 측정도구 개발과 타당도 검증)

  • Hong, Hee-Sook;Koh, Ae-Ran
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.1
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    • pp.55-67
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    • 2009
  • The purpose of this study is to develop well-being lifestyle measurement. Data were collected from a total of 251 Korean females ranging from 20 to 50 years old. The measurement items were developed by focus group interview to well-being consumers. Through a series of exploratory factor analysis and confirmatory factor analysis, the 7 sub-factors and 14 items that construct final measurement model of well-being lifestyle were identified: Health oriented eating habits, social welfare oriented consumption, interest in health policy, self-esteem enhancement, sports activity, volunteer for local community, use of cosmetics made of natural components. Fitness of measurement model and reliability and discriminant validity of measurement variables were accepted as a good level.

A procedure for simultaneous variable selection, variable transformation and outlier identification in linear regression (선형회귀에서 변수선택, 변수변환과 이상치 탐지의 동시적 수행을 위한 절차)

  • Seo, Han Son;Yoon, Min
    • The Korean Journal of Applied Statistics
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    • v.33 no.1
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    • pp.1-10
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    • 2020
  • We propose a unified approach to variable selection, transformation and outliers in the linear model. The procedure includes a sequential method for outlier detection and a least trimmed squares estimator for variable transformation. It uses all possible subsets regressions for model selection. Some real data analyses and the simulation results are provided to show the efficiency of the methods in the context of the correct variable selection and the fitness of the estimated model.

Validation of a Path Model for Adolescents' Suicidal Ideation (청소년의 자살생각 경로모형 분석)

  • Park, Yeong Sook;Kwon, Yunhee
    • Research in Community and Public Health Nursing
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    • v.24 no.3
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    • pp.255-263
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    • 2013
  • Purpose: This study examined the fitness of a path model for the relationship among daily life stress, problem of life, social support, depression, and suicidal ideation in adolescents. Methods: The subjects consisted of 247 adolescents. Data were collected through self-report questionnaires. The data were analyzed by the SPSS and AMOS programs. Results: Daily life stress, problem of life, social support, and depression showed direct effects on suicidal ideation in adolescents, while daily life stress and problem of life showed indirect effects on suicidal ideation in adolescents. Daily life stress and problem of life showed direct effects on social support and depression in adolescents. The hypothetical path model of adolescents' suicidal ideation was proven correct. Conclusion: Based on the outcomes of this study, it is necessary to design an intervention program that emphasizes the reduction of daily life stress, problem of life, depression and enhancement social support in order to prevention adolescents' suicidal ideation.

Use of a Statistical Model for Low Back Pain Rehabilitation Program Evaluation (요통환자(腰痛患者) 재활(再活) 프로그램 평가(評價)를 위한 통계적(統計的) 모형(模型))

  • Jeong, Min-Geun;Blansky, E. Richard;Addison, Robert G.
    • Journal of Korean Institute of Industrial Engineers
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    • v.14 no.2
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    • pp.63-70
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    • 1988
  • Recently a new regime, called "back school" is advocated for the purpose of rapidly and economically returning a patient to full functional fitness and normal occupational activities. Assuming that this functional and vocational restoration is a goal of a regabilitation program, it is apparent that early recovery and higher success rate are major concern. In this study, a mixture model is developed and used to evaluate the recovery process of low back pain (LBP) patients in a rehabilitation program. The model provides (1) the probability of being recovered, and (2) the rate of recovery. Patients with gradual onset, with higher education, or of young age tend to show better prognosis.

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A Hybrid PSO-BPSO Based Kernel Extreme Learning Machine Model for Intrusion Detection

  • Shen, Yanping;Zheng, Kangfeng;Wu, Chunhua
    • Journal of Information Processing Systems
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    • v.18 no.1
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    • pp.146-158
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    • 2022
  • With the success of the digital economy and the rapid development of its technology, network security has received increasing attention. Intrusion detection technology has always been a focus and hotspot of research. A hybrid model that combines particle swarm optimization (PSO) and kernel extreme learning machine (KELM) is presented in this work. Continuous-valued PSO and binary PSO (BPSO) are adopted together to determine the parameter combination and the feature subset. A fitness function based on the detection rate and the number of selected features is proposed. The results show that the method can simultaneously determine the parameter values and select features. Furthermore, competitive or better accuracy can be obtained using approximately one quarter of the raw input features. Experiments proved that our method is slightly better than the genetic algorithm-based KELM model.

Modified PSO Based Reactive Routing for Improved Network Lifetime in WBAN

  • Sathya, G.;Evanjaline, D.J.
    • International Journal of Computer Science & Network Security
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    • v.22 no.6
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    • pp.139-144
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    • 2022
  • Technological advancements taken the health care industry by a storm by embedding sensors in human body to measure their vitals. These smart solutions provide better and flexible health care to patients, and also easy monitoring for the medical practitioners. However, these innovative solutions provide their own set of challenges. The major challenge faced by embedding sensors in body is the issue of lack of infinite energy source. This work presents a meta-heuristic based routing model using modified PSO, and adopts an energy harvesting scheme to improve the network lifetime. The routing process is governed by modifying the fitness function of PSO to include charge, temperature and other vital factors required for node selection. A reactive routing model is adopted to ensure reliable packet delivery. Experiments have been performed and comparisons indicate that the proposed Energy Harvesting and Modified PSO (EHMP) model demonstrates low overhead, higher network lifetime and better network stability.