• Title/Summary/Keyword: stepwise method

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Leukocyte Segmentation using Saliency Map and Stepwise Region-merging (중요도 맵과 단계적 영역병합을 이용한 백혈구 분할)

  • Gim, Ja-Won;Ko, Byoung-Chul;Nam, Jae-Yeal
    • The KIPS Transactions:PartB
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    • v.17B no.3
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    • pp.239-248
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    • 2010
  • Leukocyte in blood smear image provides significant information to doctors for diagnosis of patient health status. Therefore, it is necessary step to separate leukocyte from blood smear image among various blood cells for early disease prediction. In this paper, we present a saliency map and stepwise region merging based leukocyte segmentation method. Since leukocyte region has salient color and texture, we create a saliency map using these feature map. Saliency map is used for sub-image separation. Then, clustering is performed on each sub-image using mean-shift. After mean-shift is applied, stepwise region-merging is applied to particle clusters to obtain final leukocyte nucleus. The experimental results show that our system can indeed improve segmentation performance compared to previous researches with average accuracy rate of 71%.

A Comparative Analysis of the Forecasting Performance of Coal and Iron Ore in Gwangyang Port Using Stepwise Regression and Artificial Neural Network Model (단계적 회귀분석과 인공신경망 모형을 이용한 광양항 석탄·철광석 물동량 예측력 비교 분석)

  • Cho, Sang-Ho;Nam, Hyung-Sik;Ryu, Ki-Jin;Ryoo, Dong-Keun
    • Journal of Navigation and Port Research
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    • v.44 no.3
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    • pp.187-194
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    • 2020
  • It is very important to forecast freight volume accurately to establish major port policies and future operation plans. Thus, related studies are being conducted because of this importance. In this paper, stepwise regression analysis and artificial neural network model were analyzed to compare the predictive power of each model on Gwangyang Port, the largest domestic port for coal and iron ore transportation. Data of a total of 121 months J anuary 2009-J anuary 2019 were used. Factors affecting coal and iron ore trade volume were selected and classified into supply-related factors and market/economy-related factors. In the stepwise regression analysis, the tonnage of ships entering the port, coal price, and dollar exchange rate were selected as the final variables in case of the Gwangyang Port coal volume forecasting model. In the iron ore volume forecasting model, the tonnage of ships entering the port and the price of iron ore were selected as the final variables. In the analysis using the artificial neural network model, trial-and-error method that various Hyper-parameters affecting the performance of the model were selected to identify the most optimal model used. The analysis results showed that the artificial neural network model had better predictive performance than the stepwise regression analysis. The model which showed the most excellent performance was the Gwangyang Port Coal Volume Forecasting Artificial Neural Network Model. In comparing forecasted values by various predictive models and actually measured values, the artificial neural network model showed closer values to the actual highest point and the lowest point than the stepwise regression analysis.

Ship Detection from Satellite Radar Imagery using Stepwise Threshold Determination (단계적 임계치 결정을 통한 위성레이더이미지 내 선박 탐지)

  • Ho-Kun Jeon;Hong Yeon Cho
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2023.05a
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    • pp.152-153
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    • 2023
  • AIS has been widely used for maritime traffic assessment for its convenience. However, AIS has problems with position missing due to radio interference and transmission distance limit. On the other hand, satellite radar determines the location of ships over a wide sea regardless of the problems. This study proposes a noble method of stepwise threshold determination to detect ships from Sentinel-1. The proposed method is up to 25 times faster than the existing moving window-based threshold determination method, and the detection accuracy is similar.

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The Study on the Production Method of Stepwise Dilution Gas for Odor Analysis with Orifice Tubes (오리피스 튜브에 의한 단계별 냄새 분석용 희석가스의 제조방법에 관한 연구)

  • Kim, Han-Soo;Lee, Seok-Jun;Kim, Sun-Tae
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.2
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    • pp.137-143
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    • 2013
  • This study is to develop the production method of stepwise dilution gas for the evaluation of complex odor concentration by orifice tube. The basic orifice tube for 10 and 30 times of dilution sample was made at first, and with the combination of the basic orifice tubes we can continuously manufacture the stepwise dilution sample gas for air dilution sensory test ; 10, 30, 100, 300, 1,000, 3,000 times etc. The hole size of orifice tube was 0.84 mm for 10 times of dilution sample, and was 0.34 mm for 30 times. Dilution sample gas made with the basic orifice tube have an excellent reproducibility, 2%RSD. In addition, over 90% of correlation was shown between the sample made by the orifice tube and the sample by the syringe dilution method. Because there was no concentration drift of dilution gas with changes of connected pump flow, the basic orifice tube could be mounted directly with a vacuum suction box, and could be used simply as a tool for the evaluation of odor, especially on site.

The Relationship between Win-Win Growth Effort and Financial Performance with Time-lag : Development of Win-Win Growth Index using Ordered Probit Model (기업의 동반성장 노력과 재무성과의 선후행 관계 : 순위 프로빗 모형을 이용한 계량적 동반성장지수의 산출)

  • Min, Jae H.;Kim, Bumseok
    • Journal of the Korean Operations Research and Management Science Society
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    • v.39 no.2
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    • pp.67-82
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    • 2014
  • The purpose of this study is two-fold : the one is to examine the causal relationship between domestic large firms' win-win growth effort and their financial performance by fiscal years; and the other is to develop a quantitative win-win growth index to overcome the limitation of the current one mainly using a survey method developed by NCCP (National Commission for Corporate Partnership). To serve the first purpose, we take a sample of 128 large companies whose win-win growth indices as of year 2011 and 2012 were evaluated by NCCP. We use their respective fiscal year's financial data to select 62 candidate financial ratios, which are then used in subsequent empirical tests. For the tests, we employ ordered probit model with stepwise selection method and two-way ANOVA with randomized block design to identify which of the 62 financial ratios are statistically significant ones to affect the firms' win-win growth index as well as to determine if the firms' win-win growth effort would cause their financial performance positively. To serve the second purpose, we devise a model using the 123 firms' 45 financial ratios, which employs ordered probit model with stepwise selection, and the validation of the model follows. We claim that the model suggested in this study serve as an alternative complementing the current one as it can produce the index in a more objective and swift manner using the firms' publicized financial statements.

Comparative Measurement of Radioactivity with Standard Gamma-ray Ionization Chamber System (표준 감마선 전리함 장치에 의한 방사능 비교 측정)

  • Park, Tae-Soon;Woo, Dong-Ho;Oh, Pil-Jae;Hwang, Sun-Tae
    • Journal of Radiation Protection and Research
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    • v.9 no.1
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    • pp.11-18
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    • 1984
  • A Standard gamma-ray ionization chamber system was developed with a well type ionization chamber and micro current measuring circuit. Micro current was measured by the automatic Townsend balance with stepwise compensation method. For gamma emitting nuclides such as $^{241}Am,\;^{133}Ba,\;^{60}Co,\;^{134}Cs,\;^{137}Cs,\;and\;^{22}Na$ relative calibration factors to $^{226}Ra$ reference source were calculated and detection .efficiency curve was determined as a fudnction of gamma energy.

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A study on Estimation of NO2 concentration by Statistical model (통계모형을 이용한 NO2 농도 예측에 관한 연구)

  • Jang Nan-Sim
    • Journal of Environmental Science International
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    • v.14 no.11
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    • pp.1049-1056
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    • 2005
  • [ $NO_2$ ] concentration characteristics of Busan metropolitan city was analysed by statistical method using hourly $NO_2$ concentration data$(1998\~2000)$ collected from air quality monitoring sites of the metropolitan city. 4 representative regions were selected among air quality monitoring sites of Ministry of environment. Concentration data of $NO_2$, 5 air pollutants, and data collected at AWS was used. Both Stepwise Multiple Regression model and ARIMA model for prediction of $NO_2$ concentrations were adopted, and then their results were compared with observed concentration. While ARIMA model was useful for the prediction of daily variation of the concentration, it was not satisfactory for the prediction of both rapid variation and seasonal variation of the concentration. Multiple Regression model was better estimated than ARIMA model for prediction of $NO_2$ concentration.

The Study on Health Promoting Lifestyle of the Elderly Women (여성노인의 건강증진 생활양식 이행의 예측요인에 관한 연구)

  • 성미혜;임영미
    • Journal of Korean Academy of Nursing
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    • v.33 no.6
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    • pp.762-771
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    • 2003
  • Purpose: This study was undertaken in order to determine factors affecting health promoting lifestyle of elderly women. Method: The subjects were 299 elderly community residing women over the age 65 living in 2 large cities. The instruments used for this study were a survey of general characteristics, health promoting lifestyle(47items), perceived health status(6 items), self-efficacy(l7 items), and social support(18 items). The data was analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and Stepwise Multiple Regression. Result: The result of the study are as follows: The average item score for the health promoting lifestyle was 2.46, the highest score on the subscale was interpersonal support(M=2.83). A significant difference between age, education level, income, experience of smoking, alcohol, exercise, and health promoting lifestyle were found. Stepwise multiple regression analysis revealed that the most powerful predictor of health promoting lifestyle was social support(55%). Conclusion: Social support accounted for 54% of the variance in health promoting lifestyle in the elderly women. Therefore, health promoting programs that increase social support should be developed to promote a healthy lifestyle of the elderly women.

Relationship between Eating Disorders, Physical Symptoms, Depression and Health Locus of Control among Elementary School Girls in South Korea (초등학교 여학생의 섭식장애, 신체증상, 우울 및 건강통제위에 관한 연구)

  • 성미혜
    • Journal of Korean Academy of Nursing
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    • v.34 no.3
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    • pp.576-585
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    • 2004
  • Purpose: The purpose of this study was to identify the relationship between eating disorders, physical symptoms, depression and health locus of control. Method: The research design was a descriptive study done by using a constructive self-report questionnaire. A total of 464 elementary school girls were measured. The instrument was a constructive questionnaire that consisted 136 items. The subjects were divided into 4 groups according to the Body Mass Index (BMI). Data analysis was done by SPSS/WIN Programs using frequency, percentage, mean, SD, ANOVA, Pearson correlation coefficient, and stepwise multiple regression. Result: The score of eating disorders differed significantly by BMI : the score was highest in the group of obese students(F=4.208, P=.015). Stepwise multiple regression analysis revealed that the most powerful predictor of eating disorders was BMI. Conclusion: These results indicate that Korean elementary school girls need more education and counseling on diet. Also, we should take systematic efforts to reestablish the social standard of beauty to promote normal growth development.

Effect of Nursing Organizational Culture on Job Satisfaction of Preceptors (간호조직문화가 프리셉터의 직무만족에 미치는 영향)

  • Yang, Nan-Young
    • Journal of Korean Academy of Nursing Administration
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    • v.12 no.4
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    • pp.597-603
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    • 2006
  • Purpose: This study was to identify effect of nursing organizational culture on job satisfaction of preceptors. Method: The subjects were 73 preceptors who were working for the 4 of university hospitals in Seoul, Daejeon and Kyong Ki. This study was conducted from Aug to Oct 2005. The data was collected by questionnaires and were analyzed using descriptive statistics, pearson correlation coefficient, stepwise multiple regression. Result: Job satisfaction of preceptors were significantly correlated among nursing organizational culture. The stepwise multiple regression analysis on job satisfaction revealed that nursing organizational culture was a powerful predictor of job satisfaction. Conclusion: The findings indicate that nursing organizational culture is important for improving job satisfaction of preceptors. Therefore it is necessary to develop of good nursing organizational culture for successful preceptorship.

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