• Title/Summary/Keyword: logistic equation

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Development of Standardized Predictive Models for Traditional Korean Medical Diagnostic Pattern Identification in Stroke Subjects: A Hospital-based Multi-center Trial

  • Jung, Woo-Sang;Cho, Seung-Yeon;Park, Seong-Uk;Moon, Sang-Kwan;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Kwon, Seungwon
    • The Journal of Korean Medicine
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    • v.40 no.4
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    • pp.49-60
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    • 2019
  • Objectives: To develop a standardized diagnostic pattern identification equation for stroke patients, our group conducted a study to derive the predictive logistic equations. However, the sample size was relatively small. In the current study, we aimed to derive new predictive logistic equations for each diagnostic pattern using an expanded number of subjects. Methods: This study was a hospital-based multi-center trial recruited stroke patients within 30 days of symptom onset. Patients' general information, and the variables related to diagnostic pattern identification were measured. The diagnostic pattern of each patient was identified independently by two Korean Medicine Doctors. To derive a predictive model for pattern identification, binary logistic regression analysis was applied. Results: Among the 1,251 patients, 385 patients (30.8%) had the Fire Heat Pattern, 460 patients (36.8%) the Phlegm Dampness Pattern, 212 patients (16.9%) the Qi Deficiency Pattern, and 194 patients (15.5%) the Yin Deficiency Pattern. After the regression analysis, the predictive logistic equations for each pattern were determined. Conclusion: The predictive equations for Fire Heat, Phlegm Dampness, Qi Deficiency, and Yin Deficiency would be useful to determine individual stroke patients' pattern identification in the clinical setting. However, further studies using objective measurements are necessary to validate these data.

A Technique of Statistical Message Filtering for Blocking Spam Message (통계적 기법을 이용한 스팸메시지 필터링 기법)

  • Kim, Seongyoon;Cha, Taesoo;Park, Jeawon;Choi, Jaehyun;Lee, Namyong
    • Journal of Information Technology Services
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    • v.13 no.3
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    • pp.299-308
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    • 2014
  • Due to indiscriminately received spam messages on information society, spam messages cause damages not only to person but also to our community. Nowadays a lot of spam filtering techniques, such as blocking characters, are studied actively. Most of these studies are content-based spam filtering technologies through machine learning.. Because of a spam message transmission techniques are being developed, spammers have to send spam messages using term spamming techniques. Spam messages tend to include number of nouns, using repeated words and inserting special characters between words in a sentence. In this paper, considering three features, SPSS statistical program were used in parameterization and we derive the equation. And then, based on this equation we measured the performance of classification of spam messages. The study compared with previous studies FP-rate in terms of further minimizing the cost of product was confirmed to show an excellent performance.

Stand Growth Estimation Using Nonlinear Growth Equations (비선형(非線型) 생장함수(生長函數)를 이용(利用)한 임분생장(林分生長) 추정(推定))

  • Son, Yeong Mo;Lee, Kyeong Hak;Chung, Young Gyo
    • Journal of Korean Society of Forest Science
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    • v.86 no.2
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    • pp.135-145
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    • 1997
  • This study aimed at evaluating one curvilinear equation and nine non-linear equations for estimating stand growth characteristics(mean dbh, mean height and volume per ha) for the plantations of Pinus koraiensis and the natural stands of Quercus mongolica. The data were collected from 92 plots in Pines koraiensis stands and 83 plots in Quercus mongolica stands, and the site index of all the stands is 14. The curvilinear equation, $Y=at^be^{-c/t}$, used in preparing the yield tables was well fitted within the range of data, but was likely to give overestimates when extrapolating in old stage due to the tendency of linear increase. Among the non-linear equations, logistic equation and Sloboda equation gave overestimates in young stands and reached the asymptotic status early which means underestimates in old stage. Extrapolating in old stage, Hossfeld equation generally gave larger values than others due to its large estimates of parameter a, the maximum value. On the other hand, Bertalanffy equation gave underestimates in young and old stands and overestimates in middle-aged stands. The estimates with Korf equation was relatively low for Pinus koraiensis stands, and this tendency was more obvious in dbh growth of Quercus mongolica stands. Ueno-Ohzaki equation was liable to give over or underestimates depending on the value of parameter b when extrapolating in old stands. Considering the accuracy of estimates and the biological base of the growth equations, Gompertz equation, Chapman-Richards equation and Weibull equation were generally applicable for estimating the stand growth characteristics of both species in the whole range of stand ages including extrapolated range. To get more accurate and precise parameter estimates, more data, especially in old stands, should be required in further study.

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Tree Size Distribution Modelling: Moving from Complexity to Finite Mixture

  • Ogana, Friday Nwabueze;Chukwu, Onyekachi;Ajayi, Samuel
    • Journal of Forest and Environmental Science
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    • v.36 no.1
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    • pp.7-16
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    • 2020
  • Tree size distribution modelling is an integral part of forest management. Most distribution yield systems rely on some flexible probability models. In this study, a simple finite mixture of two components two-parameter Weibull distribution was compared with complex four-parameter distributions in terms of their fitness to predict tree size distribution of teak (Tectona grandis Linn f) plantations. Also, a system of equation was developed using Seemingly Unrelated Regression wherein the size distributions of the stand were predicted. Generalized beta, Johnson's SB, Logit-Logistic and generalized Weibull distributions were the four-parameter distributions considered. The Kolmogorov-Smirnov test and negative log-likelihood value were used to assess the distributions. The results show that the simple finite mixture outperformed the four-parameter distributions especially in stands that are bimodal and heavily skewed. Twelve models were developed in the system of equation-one for predicting mean diameter, seven for predicting percentiles and four for predicting the parameters of the finite mixture distribution. Predictions from the system of equation are reasonable and compare well with observed distributions of the stand. This simplified mixture would allow for wider application in distribution modelling and can also be integrated as component model in stand density management diagram.

Causal Relationship of the Logistic Area for Military Service Satisfaction (군복무 만족도와 군수분야 제요소간의 인과관계 분석)

  • Kim, Woo-Hyun;Choi, Yong-Seok
    • Communications for Statistical Applications and Methods
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    • v.19 no.3
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    • pp.381-393
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    • 2012
  • This study is to understand the logistic area effect for the satisfaction of military service; service people work the unit of Marine Corps which is close or far away from North Korea and infantry people from the structural equation models based on the component based method(PLS). From the result, we note that the trustworthy and suitability of supply are the most important factors in their of military service satisfaction for Marine Corps.

Growth Modeling of Chinese Cabbage in an Alpine Area (고랭지 배추의 생장모의)

  • Ahn, Jae-Hoon;Kim, Ki-Deog;Lee, Jeoung-Tae
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.309-315
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    • 2014
  • Summer cabbages in an alpine area are very sensitive to the fluctuations in supply and demand. Yield variability due to weather conditions dictates the market fluctuations of cabbage price. This study reports an empirical relationship based on weather conditions to estimate the growth and harvestable biomass of cabbages, factors that are critical for supply of summer cabbages. Based on experimental results testing sowing date effects over the two years from 1997 to 1998, a logistic equation was parameterized to predict leaf area expansion of summer cabbages. This logistic model for leaf area expansion was then combined with an empirical allometric relationship to predict total biomass. The final equation for estimating fresh weight accumulation of Chinese cabbage is given by: $$Fresh\;weight=3500/(1+{\exp}(5.175-1.153{\times}(6/(1+{\exp}(6.367-0.0064{\times}PHU)))))$$ Where PHU is potential heat units ($^{\circ}C$). The model performance was tested using weather data from 2003 to 2006 to predict fresh harvestable biomass. Overall the model performance was satisfactory with the correlation efficient ranging between 0.89 and 0.94 for each year.

A Kinetic Study for Exopolysaccharide Production in Submerged Mycelial Culture of an Entomopathogenic Fungus Paecilomyces tenuipes C240 (동충하초 Paecilomyces tenuipes C240의 균사체 배양에 의한 세포외 다당체 생산의 동력학적 연구)

  • Xu Chung Ping;Yun Jong Won
    • Journal of Life Science
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    • v.15 no.1 s.68
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    • pp.15-20
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    • 2005
  • The unstructured model was tested to describe mycelial growth, exopolysaccharide formation, and substrate consumption in submerged mycelial culture of Paeeiliomyees tenuipes C240. The Logistic equation for mycelial growth, the Luedeking-Piret equation for exopolysaccharide formation, and Luedeking­Piret-like equations for glucose consumptions were successfully incorporated into the model. The value of the key kinetic constants were: maximum specific growth rate ${\mu}m,\;0.7281\;h^{-1};$ growth­associated constant for exopolysaccharide production $(\alpha),\;0.1743g(g\;cells)^{-1}$; non-growth associated constant for exopolysaccharide production $(\beta),\;0.0019g(g\;cells)^{-1}\;;$ maintenance coefficient $(m_s),\;0.0572g\;(g\;cells)^{-1}$. When compared with batch experimental data, the model successfully provided a reasonable description for each parameter during the entire growth phase. The model showed that the production of exopolysaccharide in P. tenuipes C240 was growth-associated. The model tested in the present study can be applied to the design, scale-up, and control of fermentation process for other kinds of basidiomycetes or ascomycetes.

Transformational Leadership and Depressive Symptoms in Germany: Validation of a Short Transformational Leadership Scale

  • Seegel, Max Leonhard;Herr, Raphael M.;Schneider, Michael;Schmidt, Burkhard;Fischer, Joachim E.
    • Journal of Preventive Medicine and Public Health
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    • v.52 no.3
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    • pp.161-169
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    • 2019
  • Objectives: The objective of the present study was to validate a shortened transformational leadership (TL) scale (12 items) comprising core TL behaviour and to test the associations of this shortened TL scale with depressive symptoms. Methods: The study used cross-sectional data from 1632 employees of the overall workforce of a middle-sized German company (51.6% men; mean age, 41.35 years; standard deviation, 9.4 years). TL was assessed with the German version of the Transformational Leadership Inventory and depressive symptoms with the Hospital Anxiety and Depression Scale (HADS). The structural validity of the core TL scale was assessed with confirmatory factor analysis. Associations with depressive symptoms were estimated with structural equation modelling and adjusted logistic regression. Results: Confirmatory factor analysis and structural equation modelling showed better model fit for the core TL than for the full TL score. Logistic regression revealed 3.61-fold (95% confidence interval [CI], 2.20 to 5.93: women) to 4.46-fold (95% CI, 2.86 to 6.95: men) increased odds of reporting depressive symptoms (HADS score >8) for those in the lowest tertile of reported core TL. Conclusions: The shortened core TL seems to be a valid instrument for research and training purposes in the context of TL and depressive symptoms in employees. Of particular note, men reporting poor TL were more likely to report depressive symptoms.

A three-dimensional patent evaluation model that considers the factors for calculating the internal and external value of a patent: Arrhenius chemical reaction kinetics-based patent lifespan prediction (특허의 내적.외적 가치산정요인을 고려한 입체적 특허평가모델: 아레니우스 화학반응속도론 기반의 특허수명예측)

  • Choi, Yong Muk;LEE, JAEWON;Cho, Daemyeong
    • Journal of Digital Convergence
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    • v.19 no.6
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    • pp.113-132
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    • 2021
  • This study is a new evaluation using the Arrhenius equation, which is known as the chemical reaction rate estimation equation, to evaluate the intrinsic and extrinsic value elements of patents as a model. The performance of the evaluation model was superior to the SVM, Logistic reg. and ANN models that were used as patent evaluation models in prior studies. In addition, there was a strong correlation between the predicted lifespan of the patent and the actual lifespan of the patent. These evaluation models may be used for evaluation purposes only, or if an evaluation is required, including a commercialization entity or technical characteristics.

Dietary supplement use and its related factors among Chinese international and Korean college students in South Korea

  • Linxi Huang;Hye-Jong Yoo;Satoko Abe;Jihyun Yoon
    • Nutrition Research and Practice
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    • v.17 no.2
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    • pp.341-355
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    • 2023
  • BACKGROUND/OBJECTIVES: The consumption of dietary supplements has shown an increase among young people in their 20s. We aimed to compare the use of dietary supplements and related factors between Chinese international and Korean college students living in South Korea. SUBJECTS/METHODS: We conducted online surveys of 400 Chinese international students and 452 Korean college students from January to February 2021. We analyzed the factors related to the use of dietary supplements by these students using multi-group structural equation modeling and logistic regression analysis. RESULTS: Approximately 65% of the Chinese international students and 93% of the Korean college students consumed dietary supplements at least once in the year preceding the survey. The common types of dietary supplements consumed by both groups of students were vitamin and mineral supplements, Lactobacillus products, and red ginseng products. Structural equation modeling showed that perception of the consumption of dietary supplements by family and friends positively influenced attitude toward dietary supplements. This effect was higher for Korean college students than for Chinese international students (P < 0.01). Attitude toward dietary supplements positively influenced their use, and this effect was higher for Chinese international students than for Korean college students (P < 0.001). Logistic regression analysis showed that the use of dietary supplements by Chinese international students was significantly associated with age, self-reported health status, interest in health, perception of and attitude toward dietary supplements, and length of residence in South Korea. Among Korean college students, it was associated with exercise frequency and attitude toward dietary supplements. CONCLUSION: This study showed significant differences in the use of dietary supplements and related factors between Chinese international and Korean college students. Therefore, nutrition education programs on dietary supplements need to have differentiated content for each group. Such differences also suggest that the industry should consider the relevant characteristics of college students while developing and marketing dietary supplements.