• Title/Summary/Keyword: 로지스틱모델

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Urban Growth Prediction each Administrative District Considering Social Economic Development Aspect of Climate Change Scenario (기후변화시나리오의 사회경제발전 양상을 고려한 행정구역별 도시성장 예측)

  • Kim, Jin Soo;Park, So Young
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.2
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    • pp.53-62
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    • 2013
  • Land-use/cover changes not only amplify or alleviate influence of climate changes but also they are representative factors to affect environmental change along with climate changes. Thus, the use of land-use/cover changes scenario, consistent climate change scenario is very important to evaluate reliable influences by climate change. The purpose for this study is to predict and analyze the future urban growth considering social and economic scenario from RCP scenario suggested by the 5th evaluation report of IPCC. This study sets land-use/cover changes scenario based on storyline from RCP 4.5 and 8.5 scenario. Urban growth rate for each scenario is calculated by urban area per person and GDP for the last 25 years and regression formula based on double logarithmic model. In addition, the urban demand is predicted by the future population and GDP suggested by the government. This predicted demand is spatially distributed by the urban growth probability map made by logistic regression. As a result, the accuracy of urban growth probability map is appeared to be 89.3~90.3% high and the prediction accuracy for RCP 4.5 showed higher value than that of RCP 8.5. Urban areas from 2020 to 2050 showed consistent growth while the rate of increasing urban areas for RCP 8.5 scenario showed higher value than that of RCP 4.5 scenario. Increase of urban areas is predicted by the fact that famlands are damaged. Especially RCP 8.5 scenario indicated more increase not only farmland but also forest than RCP 4.5 scenario. In addition, the decrease of farmland and forest showed higher level from metropolitan cities than province cities. The results of this study is believed to be used for basic data to clarify complex two-way effects quantitatively for future climate change, land-use/cover changes.

Analysis and Management of Potential Development Area Using Factor of Change from Forest to Build-up (산림의 시가지 변화요인을 통한 잠재개발지 분석 및 관리방안)

  • LEE, Ji-Yeon;LIM, No-Ol;LEE, Sung-Joo;CHO, Hyo-Jin;SUNG, Hyun-Chan;JEON, Seong-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.25 no.2
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    • pp.72-87
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    • 2022
  • For the sustainable development and conservation of the national land, planned development and efficient environmental conservation must be accompanied. To this end, it is possible to induce development and conservation to harmonize by deriving factors affecting development through analysis of previously developed areas and applying appropriate management measures to areas with high development pressure. In this study, the relationship between the area where the land cover changed from forest to urbanization and various social, geographical, and restrictive factors was implemented in a regression formula through logistic regression analysis, and potential development sites were analyzed for Yongin City. The factor that has the greatest impact on the analysis of potential development area is the restrict factors such as Green Belt and protected areas, and the factor with the least impact is the population density. About 148km2(52%) of Yongin-si's forests were analyzed as potential development area. Among the potential development sites, the area with excellent environmental value as a protected area and 1st grade on the Environment Conservation Value Assessment Map was derived as about 13km2. Protected areas with high development potential were riparian buffer zone and special measurement area, and areas with excellent natural scenery and river were preferred as development areas. Protected areas allow certain actions to protect individual property rights. However, there is no clear permit criteria, and the environmental impact of permits is not understood. This is identified as a factor that prevents protected areas from functioning properly. Therefore, it needs to be managed through clear exception permit criteria and environmental impact monitoring.

The prediction of the stock price movement after IPO using machine learning and text analysis based on TF-IDF (증권신고서의 TF-IDF 텍스트 분석과 기계학습을 이용한 공모주의 상장 이후 주가 등락 예측)

  • Yang, Suyeon;Lee, Chaerok;Won, Jonggwan;Hong, Taeho
    • Journal of Intelligence and Information Systems
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    • v.28 no.2
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    • pp.237-262
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    • 2022
  • There has been a growing interest in IPOs (Initial Public Offerings) due to the profitable returns that IPO stocks can offer to investors. However, IPOs can be speculative investments that may involve substantial risk as well because shares tend to be volatile, and the supply of IPO shares is often highly limited. Therefore, it is crucially important that IPO investors are well informed of the issuing firms and the market before deciding whether to invest or not. Unlike institutional investors, individual investors are at a disadvantage since there are few opportunities for individuals to obtain information on the IPOs. In this regard, the purpose of this study is to provide individual investors with the information they may consider when making an IPO investment decision. This study presents a model that uses machine learning and text analysis to predict whether an IPO stock price would move up or down after the first 5 trading days. Our sample includes 691 Korean IPOs from June 2009 to December 2020. The input variables for the prediction are three tone variables created from IPO prospectuses and quantitative variables that are either firm-specific, issue-specific, or market-specific. The three prospectus tone variables indicate the percentage of positive, neutral, and negative sentences in a prospectus, respectively. We considered only the sentences in the Risk Factors section of a prospectus for the tone analysis in this study. All sentences were classified into 'positive', 'neutral', and 'negative' via text analysis using TF-IDF (Term Frequency - Inverse Document Frequency). Measuring the tone of each sentence was conducted by machine learning instead of a lexicon-based approach due to the lack of sentiment dictionaries suitable for Korean text analysis in the context of finance. For this reason, the training set was created by randomly selecting 10% of the sentences from each prospectus, and the sentence classification task on the training set was performed after reading each sentence in person. Then, based on the training set, a Support Vector Machine model was utilized to predict the tone of sentences in the test set. Finally, the machine learning model calculated the percentages of positive, neutral, and negative sentences in each prospectus. To predict the price movement of an IPO stock, four different machine learning techniques were applied: Logistic Regression, Random Forest, Support Vector Machine, and Artificial Neural Network. According to the results, models that use quantitative variables using technical analysis and prospectus tone variables together show higher accuracy than models that use only quantitative variables. More specifically, the prediction accuracy was improved by 1.45% points in the Random Forest model, 4.34% points in the Artificial Neural Network model, and 5.07% points in the Support Vector Machine model. After testing the performance of these machine learning techniques, the Artificial Neural Network model using both quantitative variables and prospectus tone variables was the model with the highest prediction accuracy rate, which was 61.59%. The results indicate that the tone of a prospectus is a significant factor in predicting the price movement of an IPO stock. In addition, the McNemar test was used to verify the statistically significant difference between the models. The model using only quantitative variables and the model using both the quantitative variables and the prospectus tone variables were compared, and it was confirmed that the predictive performance improved significantly at a 1% significance level.

A Study on The Factors Influencing the Decision to Get Implant Treatment at Dental Clinic (치과의원에서 임플란트 치료 결정에 영향을 미치는 요인에 관한 연구)

  • Oh, Hye-Young;Jin, Ki-Nam
    • Journal of dental hygiene science
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    • v.12 no.2
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    • pp.85-91
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    • 2012
  • The purpose of this study was to examine the factors influencing the decision to get implant treatment at dental clinic. The subjects in this study were 321 patients at dental hospitals and clinics. Andersen model in which predisposing variables, enabling variables and need variables were suggested as independent variables was used. The implant decision making was selected as a dependent variable in the model. Using logistic regression analysis, we found statistically significant effects of three independent variables: 1) class, 2) satisfaction with the facility; 3) familiarity with others received implant treatment. Those with the middle or high class background were more likely to take implant treatment. Those who were satisfied with clinic facility were more likely to take implant treatment. Those who were familiar with others received implant treatment were more likely to take implant treatment. This result implies the importance of opinion of others were received the same treatment. Hence viral marketing effort is required even in dental care field.

An Empirical Study on the Determinants of Customer Renewal Behavior for Tire Rental Servitization (제조기업의 서비스화 제공 형태와 고객 특성이 재계약에 미치는 요인에 관한 실증 연구: 타이어 렌탈 중심으로)

  • Hyun, Myungjin;Kim, Jieun
    • The Journal of the Korea Contents Association
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    • v.20 no.4
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    • pp.508-517
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    • 2020
  • Servitization presents an innovative model to create business value in the automotive industries. This study set out to introduce a servitization model based on the rental business of the tire industry and identify determinants to affect the renewal of contracts around the service types of servitization and the characteristics of customers. Independent variables include the service types, demographics and regions, and inflow channels in 163,742 contracts by case companies in the nation in 2016~2019 with the renewal of contracts as a dependent variable. Correlations between variables were analyzed through cross-tabulation and binary logistic regression analysis. The findings show that the contract renewal rate had positive(+) relations with customized service and negative(-) ones with vehicle maintenance service. There were differences in the contract renewal rate according to such customer characteristics as gender and region, but no clear correlations were found in the age group and vehicle type(domestic/foreign). Of the inflow channels, offline channels tended to have a higher renewal rate than online channels. At open malls, contract renewal increased by 8.4 times due to contract switches at offline channels. Based on these findings, the study discussed directions for practical strategies with regard to the development of new service, implementation of customer-centric servitization, and management of sales channels according to the servitization of manufacturers.

Determination of Removal Time of the Side Form in High Strength Concrete (고강도콘크리트 시공시 측면 거푸집 탈형시기의 결정)

  • Han Cheon-Goo;Han Min-Cheol
    • Journal of the Korea Concrete Institute
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    • v.16 no.3 s.81
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    • pp.327-334
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    • 2004
  • In this paper, method for the determination of removal time of the side forms in high strength concrete are discussed using the estimation model of compressive strength development, the development of bond strength and rebound number of P type Schmidt hammer in order to review the validity of existing regulation as to side form removal and offer effective quality control method. According to the results, as W/B increases by $10\%$, the setting time is shortened by about 2 hours. In the scope of the paper, required time to gain 8MPa of compressive strength is determined about 17 ${\~}$20 hours of age and $21{\~}25^{\circ}D{\cdot}D$ of maturity. Bond strength between form and concrete shows the highest value around final setting time, but decreases drastically after that. Amount of concrete sticking on the form is large before setting completed, but after that, its amount shows decline tendency. The rebound value test with P type schmidt hammer can be started faster by 2${\~}$3 hours than compressive strength test. It is also confirmed that the removal of forms is possible when the rebound value of P type schmidt hammer is more than 32. It is found from the results that existing regulation regarding removal time of the side form of high strength concrete provided in KCI needs no revision because required time to gain the strength provided in KCI has no adverse effect on strength development at early age and surface condition during stripping the side form. Effective procedure to decide the removal time of side form can be performed by applying P type Schmidt hammer.

Factors Affecting the Adjustment of Children from Maritally Violent Homes : An Exploratory Analysis Focusing on Children Living in Shelters for Battered Women (아내폭력가정 자녀의 적응에 영향을 미치는 요인들 : 쉼터 거주 아동을 중심으로)

  • Chang, Hee-Suk
    • Korean Journal of Social Welfare
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    • v.55
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    • pp.255-281
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    • 2003
  • This study sought to explore factors affecting the adjustment of children living in shelters for battered women. Specifically, the impact of domestic violence on children's internal and external adjustment was examined using data from two samples: children who were exposed to marital violence and those who did not have violent experience. Likewise, this study identified the variables that distinguished the "resilient" children from the maladjusted group. The pathways by which protective factors considerably affected children's adjustment were also investigated. A total of 72 children in a women's shelter and their mothers and 76 children in nonviolent homes and their mothers were considered. ANOVA, logistic regression models, and path analysis were employed to process the data. Results revealed that children of battered women demonstrated a high frequency of aggressive and delinquent behaviors and had poor academic achievement and depressive mood compared to children coming from nonviolent homes. Likewise, children who were exposed to marital violence and were physically abused themselves were more likely show aggressive or delinquent behaviors compared to those who only witnessed marital violence. In addition, social support was found to be a protective factor in academic achievement. Predictors of delinquent behavior included the mother's education and income as well as the children's age and social support. Factors related to children's self-esteem included the social support and the mother's self-esteem. Moreover, woman battering has a direct effect on children's adjustment as well as indirect effect through children's academic achievement and self-esteem. Finally, woman battering indirectly affected children's academic achievement through the mother's depression or the child's social support. Based on these findings, practical implications of enhancing children's adjustment were discussed.

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Estimating the Global Inflow and Stock of Plastic Marine Debris Using Material Flow Analysis: a Preliminary Approach (물질흐름분석을 활용한 전세계 플라스틱 해양쓰레기의 유입량과 현존량 추정: 예비적 접근)

  • Jang, Yong Chang;Lee, Jongmyoung;Hong, Sunwook;Choi, Hyun Woo;Shim, Won Joon;Hong, Su Yeon
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.18 no.4
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    • pp.263-273
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    • 2015
  • We estimated the global inflow and stock of plastic marine debris. In South Korea, we estimated that the annual inflow of plastic marine debris (72,956 tons) was about 1.4% of annual plastics consumption (5.2 million tons) in 2012. By applying this 1.4% ratio to global plastics production from 1950 to 2013, we estimated that 4.2 million tons of plastic debris entered the ocean in 2013 and that there is a stock of 86 million tons of plastic marine debris as of the end of 2013, assuming zero outflow. In addition, with a logistic model, if 4% of petroleum is turned into plastics, the final stock of plastic marine debris shall be 199 million tons at the end. As the inflow and the stock are different units of measurement, better indicators to assess the effectiveness of inflow-reducing policies are needed. And, as the pollution from plastic marine debris is almost irreversible, countermeasures to prevent it should be valued more, and stronger preventive measures should be taken under the precautionary principle. As this is a preliminary study based on limited information, further research is needed to clarify the tendency of inflow and stock of plastic marine debris.

Analysis of Feature Importance of Ship's Berthing Velocity Using Classification Algorithms of Machine Learning (머신러닝 분류 알고리즘을 활용한 선박 접안속도 영향요소의 중요도 분석)

  • Lee, Hyeong-Tak;Lee, Sang-Won;Cho, Jang-Won;Cho, Ik-Soon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.2
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    • pp.139-148
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    • 2020
  • The most important factor affecting the berthing energy generated when a ship berths is the berthing velocity. Thus, an accident may occur if the berthing velocity is extremely high. Several ship features influence the determination of the berthing velocity. However, previous studies have mostly focused on the size of the vessel. Therefore, the aim of this study is to analyze various features that influence berthing velocity and determine their respective importance. The data used in the analysis was based on the berthing velocity of a ship on a jetty in Korea. Using the collected data, machine learning classification algorithms were compared and analyzed, such as decision tree, random forest, logistic regression, and perceptron. As an algorithm evaluation method, indexes according to the confusion matrix were used. Consequently, perceptron demonstrated the best performance, and the feature importance was in the following order: DWT, jetty number, and state. Hence, when berthing a ship, the berthing velocity should be determined in consideration of various features, such as the size of the ship, position of the jetty, and loading condition of the cargo.

Relationship Between Job Stress and Fatigue Symptoms Among Nurses in a University Hospital (대학병원 간호사들의 직무스트레스와 피로수준과의 관련성)

  • Kim, Soon-Young;Kwon, In-Sun;Cho, Young-Chae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1759-1768
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    • 2012
  • The present study was intended to measure the level of fatigue symptoms among nurses working for a university hospital and to reveal its related factors. The self-administered questionnaires were given to 450 nurses during the period from October 1st to 31st, 2010. As a results, the level of fatigue symptoms were 75.1% in normal group, and the high-risk group 24.9%. The level of fatigue symptoms reflected in job stress contents were higher as job demand was higher, and the autonomy of job and the supervisor support was lower. In correlations, fatigue symptoms were found to be in a positive correlation with job demand, whereas in negative correlation with autonomy of job and supervisor support. The adjusted odds ratio of fatigue symptoms on job demand were significantly increased in the high risk group than in low group, but autonomy of job. were significantly decreased in the high risk group than in low group. In conclusion, the study results indicated that the level of fatigue symptoms is independently influenced by job stress contents.