• 제목/요약/키워드: principal component regression

Search Result 251, Processing Time 0.03 seconds

The Effect of the Government Policy on Foreign Trade of Zhengzhou (중국 정주시의 대외무역에 관한 연구)

  • Li, Feng Ji;Kim, Young-Min
    • The Journal of the Convergence on Culture Technology
    • /
    • v.6 no.4
    • /
    • pp.295-300
    • /
    • 2020
  • Since China opened its door to the world in 1978, its economic development had been concentrated in the Eastern and Western area compared with the middle area. From 2000s, the Chinese government started to develop the middle area in terms of balanced development. With this goal, "Plan on Zhengzhou Airport Economy Zone", and "One Belt and One Road" has implemented in Zhengzhou, where is the an important traffic center in middle area. Meanwhile, the foreign trade of Zhengzhou has been increased about 10 times between 2009 and 2018. In particular, its growth is the fastest among six central cities in 2018 from the lowest in 2009. This study investigates whether the Chinese government policy has an effect on the foreign trade of Zhengzhou. We find that based on the regression analysis of the Principal Component Analysis (PCA), the government policies has a positive impact on the development of Zhengzhou's foreign trade. It is meaningful that the government policy focused on the advantage of Zhengzhou contributes its development of foreign trade.

Prediction Models for Solitary Pulmonary Nodules Based on Curvelet Textural Features and Clinical Parameters

  • Wang, Jing-Jing;Wu, Hai-Feng;Sun, Tao;Li, Xia;Wang, Wei;Tao, Li-Xin;Huo, Da;Lv, Ping-Xin;He, Wen;Guo, Xiu-Hua
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.10
    • /
    • pp.6019-6023
    • /
    • 2013
  • Lung cancer, one of the leading causes of cancer-related deaths, usually appears as solitary pulmonary nodules (SPNs) which are hard to diagnose using the naked eye. In this paper, curvelet-based textural features and clinical parameters are used with three prediction models [a multilevel model, a least absolute shrinkage and selection operator (LASSO) regression method, and a support vector machine (SVM)] to improve the diagnosis of benign and malignant SPNs. Dimensionality reduction of the original curvelet-based textural features was achieved using principal component analysis. In addition, non-conditional logistical regression was used to find clinical predictors among demographic parameters and morphological features. The results showed that, combined with 11 clinical predictors, the accuracy rates using 12 principal components were higher than those using the original curvelet-based textural features. To evaluate the models, 10-fold cross validation and back substitution were applied. The results obtained, respectively, were 0.8549 and 0.9221 for the LASSO method, 0.9443 and 0.9831 for SVM, and 0.8722 and 0.9722 for the multilevel model. All in all, it was found that using curvelet-based textural features after dimensionality reduction and using clinical predictors, the highest accuracy rate was achieved with SVM. The method may be used as an auxiliary tool to differentiate between benign and malignant SPNs in CT images.

A Study on the Origin of Organic Matter in Seawater in Korean Estuaries Using Chemical Oxygen Demand (화학적산소요구량을 이용한 하구해역의 해수중 유기물 기원 고찰)

  • Kim, Young-Sug;Koo, Jun-Ho;Kwon, Jung-No;Lee, Won-Chan
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.24 no.6
    • /
    • pp.735-749
    • /
    • 2018
  • In this study, one studied the principal factors and water-quality components that determine the concentration of chemical oxygen demand (COD) in seawater in estuaries, such as the Han, Geum, Youngsan, Seomjin, and Nakdong rivers in Korea. The principal factors determining the concentration of COD in seawater indicated by the principal component analysis were salinity, exogenous origin and autochthonous resources based on chlorophyll-a. Moreover, organic matter in the submarine sediment layer also had a secondary effect. Regression slope assessed the contribution of water-quality components to determine the concentration of COD in the estuary. One found that the effect of salinity on the overall survey was significant. Moreover, the effect of chlorophyll-a was also appeared in April and August. In each estuary, the most significant contribution factor was chlorophyll-a in the Nakdong River and salinity in the Han and Yongsan rivers. The contribution of salinity and chlorophyll-a were found to be the largest in the Geum River. The salinity and chlorophyll-a in the Seomjin River showed a low contribution.

A Study on the Factors Influencing on the Conflicts Perceived by Franchise (프랜차이즈 유통경로상의 갈등에 영향을 미치는 요인에 관한 연구 : 슈퍼바이저의 상거래태도와 업무전문성의 조절효과를 중심으로)

  • Yang, Xiao-Peng;Park, Chan-Wook
    • Journal of Distribution Science
    • /
    • v.14 no.7
    • /
    • pp.91-100
    • /
    • 2016
  • Purpose - Recently actively growing franchise systems distribution channel system in which franchise headquarter compared with franchise occupies an important place in distribution channel. Due to this, franchise and franchise headquarter are interdependent on task and in this situation the goal they go after, motivation and objective are probably inconsistent. If so, possibility to participate goal setting process or operating activity of opposite side is becoming bigger and in the end conflict may generate. The purpose of this study is to examine the role of the supervisor's attitude and expertise as moderating factors in the relationship between goal-incongruity/coercive power/role-incongruity and the conflict perceived by franchisee. Research design, data and methodology - This study was intended to verify how the supervisor's attitude and expertise as moderating factors in the relationship between goal-incongruity/coercive power/role-incongruity and the conflict perceived by franchisee. In order to achieve the purpose of this study, some study models and hypotheses have been established through theoretical examinations. Then, using these scales, the researcher completed the questionnaire survey. To test our hypotheses, the survey was conducted from March 9, 2016 for 20 days by random sampling, The study was implemented through a descriptive survey method using a self-administered questionnaire. A survey of 124 restaurant franchisee across Seoul and Gyeonggi Province was performed. A total of 124 completed responses were analyzed. In this study, I used SPSS 22.0 to analyze data and did frequency analysis to see demographic, and general features of the respondents; also did exploratory factor analysis to examine the validity of the items of measurement. Factor analysis was first calculated at a minimum, the number of factors, principal component analysis used when variables are committed to maximising the information with (principle component analysis) and the rotation of factors were angry about the great variable factors than 1.0 by applying Varimax rotation. In addition, I used the value of Cronbach's (Alpha) to examine the reliance of questionnaire items, final analysis the reliability factor can be found both high reliability hayeoteumeuro exceeds over 0.6 and did Multiple regression analysis to test hypothesis and also did hierarchical regression analysis to examine moderating effect. Results - To analyze the proposed model, according to the analysis result, it was found that the influence of goal-incongruity, coercive power, and role-incongruity on the perceived conflict of franchisee is moderated by the supervisor's attitude and expertise. That is, the more the supervisor's attitude and expertise were positive, the more the conflicts of the goal-incongruity, coercive power, and role-incongruity were decreased. It also confirmed previous research's finding that goal-incongruity, coercive power, and role-incongruity positively influence on the conflict. Conclusions - According to the results of this research which reduces the conflict of franchise from the in consistent goal; coercive power, and inconsistent role of superiors, it provides very important implications for franchise headquarter which has franchise system and also give them some suggestion about how to recruit superiors and what kind of training may be fit for the superiors.

Characterization of Concentrations of Fine Particulate Matter in the Atmosphere of Pohang Area (포항지역 대기 중 초미세먼지(PM$_{2.5}$)의 오염특성평가)

  • Baek, Sung-Ok;Heo, Yoon-Kyeung;Park, Young-Hwa
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.30 no.3
    • /
    • pp.302-313
    • /
    • 2008
  • The purposes of this study are to investigate the concentration levels of fine particles, so called PM$_{2.5}$, to identify the affecting sources, and to estimate quantitatively the source contributions of PM$_{2.5}$. Ambient air sampling was seasonally carried out at two sites in Pohang(a residential and an industrial area) during the period of March to December 2003. PM$_{2.5}$ samples were collected by high volume air samplers with a PM$_{10}$ Inlet and an impactor for particle size segregation, and then determined by gravimetric method. The chemical species associated with PM$_{2.5}$ were analyzed by inductively coupled plasma spectrophotometery(ICP) and ion chromatography(IC). The results showed that the most significant season for PM$_{2.5}$ mass concentrations appeared to be spring, followed by winter, fall, and summer. The annual mean concentrations of PM$_{2.5}$ were 36.6 $\mu$g/m$^3$ in the industrial and 30.6 $\mu$g/m$^3$ in the residential area, respectively. The major components associated with PM$_{2.5}$ were the secondary aerosols such as nitrates and sulfates, which were respectively 4.2 and 8.6 $\mu$g/m$^3$ in the industrial area and 3.7 and 6.9 $\mu$g/m$^3$ in the residential area. The concentrations of chemical component in relation to natural emission sources such as Al, Ca, Mg, K were generally higher at both sampling sites than other sources. However, the concentrations of Fe, Mn, Cr in the industrial area were higher than those in the residential area. Based on the principal component analysis and stepwise multiple linear regression analysis for both areas, it was found that soil/road dust and secondary aerosols are the most significant factors affecting the variations of PM$_{2.5}$ in the ambient air of Pohang. The source apportionments of PM$_{2.5}$ were conducted by chemical mass balance(CMB) modeling. The contributions of PM$_{2.5}$ emission sources were estimated using the CMB8.0 receptor model, resulting that soil/road dust was the major contributor to PM$_{2.5}$, followed by secondary aerosols, vehicle emissions, marine aerosols, metallurgy industry. Finally, the application and its limitations of chemical mass balance modeling for PM$_{2.5}$ was discussed.

Wave and surface current measurement with HF radar in the central east coast of Korea (동해중부에서 HF Radar를 이용한 파랑 및 해수유동 관측)

  • Kim, Moo-Hong;Kim, Gyung-Soo;Kim, Hyeon-Seong
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.38 no.6
    • /
    • pp.771-780
    • /
    • 2014
  • We installed HF Radar of Array type in Site A and Site B, observing the real-time wave and current in the central East coast of Korea. WERA(WavE RAdar) in this research uses HF Radar of Array Type with frequency range of 24.525 MHz, developed by Helzel, Germany. Each site is a 8-Channel system consisting of four transmitters and eight receivers, generating wave and current data, being observed every thirty minutes at the present time. HF Radar has grid resolution of an interval of 1.5 km using bandwidth of 150 kHz; The wave data covers an observation range of about 25 km, and the current data covers the maximum observation range of about 50 km. The Wave data observed by HF Radar was compared and verified with the AWAC data observed in the research sites. MIT also compared the Current data observed by HF Radar with Monthly the East sea average surface current and current flow pattern provided by KOHA(Korea Hydrographic and oceanographic Administration). The regression line and deviation of the comparison data of Wave was calculated by Principal Component Analysis, which showed correlation coefficient 0.86 and RMSD 0.186. Besides, data analysis of long-term changes of the current in the East coast showed that, during August and September, the North Korean Cold Current flow into the southward direction and the East Korean Warm Current flow into the northward direction in the coast.

Accuracy of HF radar-derived surface current data in the coastal waters off the Keum River estuary (금강하구 연안역에서 HF radar로 측정한 유속의 정확도)

  • Lee, S.H.;Moon, H.B.;Baek, H.Y.;Kim, C.S.;Son, Y.T.;Kwon, H.K.;Choi, B.J.
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.13 no.1
    • /
    • pp.42-55
    • /
    • 2008
  • To evaluate the accuracy of currents measured by HF radar in the coastal sea off Keum River estuary, we compared the facing radial vectors of two HF radars, and HF radar-derived currents with in-situ measurement currents. Principal component analysis was used to extract regression line and RMS deviation in the comparison. When two facing radar's radial vectors at the mid-point of baseline are compared, RMS deviation is 4.4 cm/s in winter and 5.4 cm/s in summer. When GDOP(Geometric Dilution of Precision) effect is corrected from the RMS deviations that is analyzed from the comparison between HF radar-derived and current-metermeasured currents, the error of velocity combined by HF radar-derived current is less than 5.1 cm/s in the stations having moderate GDOP values. These two results obtained from different method suggest that the lower limit of HF radar-derived current's accuracy is 5.4 cm/s in our study area. As mentioned in previous researches, RMS deviations become large in the stations located near the islands and increase as a function of mean distance from the radar site due to decrease of signal-to-noise level and the intersect angle of radial vectors. We found that an uncertain error bound of HF radar-derived current can be produced from the separation process of RMS deviations using GDOP value if GDOP value for each component is very close and RMS deviations obtained from current component comparison are also close. When the current measured in the stations having moderate GDOP values is separated into tidal and subtidal current, characteristics of tidal current ellipses analyzed from HF radar-derived current show a good agreement with those from current-meter-measured current, and time variation of subtidal current showed a response reflecting physical process driven by wind and density field.

Apartment Price Prediction Using Deep Learning and Machine Learning (딥러닝과 머신러닝을 이용한 아파트 실거래가 예측)

  • Hakhyun Kim;Hwankyu Yoo;Hayoung Oh
    • KIPS Transactions on Software and Data Engineering
    • /
    • v.12 no.2
    • /
    • pp.59-76
    • /
    • 2023
  • Since the COVID-19 era, the rise in apartment prices has been unconventional. In this uncertain real estate market, price prediction research is very important. In this paper, a model is created to predict the actual transaction price of future apartments after building a vast data set of 870,000 from 2015 to 2020 through data collection and crawling on various real estate sites and collecting as many variables as possible. This study first solved the multicollinearity problem by removing and combining variables. After that, a total of five variable selection algorithms were used to extract meaningful independent variables, such as Forward Selection, Backward Elimination, Stepwise Selection, L1 Regulation, and Principal Component Analysis(PCA). In addition, a total of four machine learning and deep learning algorithms were used for deep neural network(DNN), XGBoost, CatBoost, and Linear Regression to learn the model after hyperparameter optimization and compare predictive power between models. In the additional experiment, the experiment was conducted while changing the number of nodes and layers of the DNN to find the most appropriate number of nodes and layers. In conclusion, as a model with the best performance, the actual transaction price of apartments in 2021 was predicted and compared with the actual data in 2021. Through this, I am confident that machine learning and deep learning will help investors make the right decisions when purchasing homes in various economic situations.

A Development of a Forecasting System of Textile Design based on Consumer Emotion(I) - Suggestion of an Efficient Textile Design Method - (소비자 감성에 기반한 텍스타일디자인 예측시스템 개발(I) - 효율적인 텍스타일디자인 방법 제안 -)

  • Cho, Hyun-Seung;Lee, Joo-Hyeon
    • Fashion & Textile Research Journal
    • /
    • v.7 no.2
    • /
    • pp.187-195
    • /
    • 2005
  • The purposes of this study were to investigate the effects of the elements of textile design on consumer emotion and to develop the emotion model which is suitable for the textile design. The descriptive system of textile design was developed based on the previous studies. Emotion measurement scale was developed to analyze the consumer emotion for the textile design. 20 representative types of textile design were collected as stimuli set for this study, consumer emotion on each design type was examined and was analyzed through the survey. For the data analysis, principal component analysis was employed. As a result, 8 emotional factors such as 'Modern', 'Fun', 'Natural', 'Elegance', 'Classic', 'Ethnic', 'Wild' and 'Sporty' were derived from the results of the survey. Emotion measurement scale which consisted of 8 factors was developed to analyze the effects of the elements of textile design on consumer emotion and 80 representative types of textile design were collected. In addition, the emotion which consumers feel for the textile design types was investigated and each textile design was described according to the descriptive system of textile design. Statistical methods of pearson correlation and multiple regression were employed to analyze the relationship between the elements of textile design and consumer emotion. The results of this study revealed that 15 design elements which affected consumer emotion were the size of motives, the shape of motives, the degree of tone contrast among motives etc. This study findings can provide specific design methods for the effectiveness of consumer emotion.

Pharmacists' Perceptions of Barriers to Providing Appropriate Pharmaceutical Services in Community Pharmacies (지역약국 약료서비스 제공의 장애요인: 약사 대상 설문조사)

  • Sohn, Hyun Soon;Kim, Seong-Ok;Joo, Kyung-Mi;Park, Hyekyung;Han, Euna;Ahn, Hyung Tae;Choi, Sang-Eun
    • Korean Journal of Clinical Pharmacy
    • /
    • v.25 no.2
    • /
    • pp.94-101
    • /
    • 2015
  • Background: In order to achieve the goals of community pharmacy practice, its legal, labour-related, and economic barriers need to be identified. This study examined pharmacists' perceptions of constraints on providing optimal pharmacy services in order to identify underlying factors and analyse the associations between barriers and pharmaceutical services in community pharmacies. Methods: A survey targeting pharmacy owners was conducted from May to June 2012 using a structured questionnaire including nine pharmaceutical service items. According to the service provision level, we classified pharmacists as inactive (fewer than 5 items among the listed 9 service items) and active providers (5 or more items). Principal component analysis was used to group significant factors for barriers into four thematic components. Associations between the participants' demographics and pharmacy characteristics and the services provided were explored by logistic regression analyses. Results: Participants were 402 pharmacists. Over 60% provided disease management services for hypertension, diabetes, and hyperlipidaemia. Variables that affected pharmaceutical services included the lack of separate areas for patient counselling (OR: 2.12, 95% CI: 1.18-3.80), and clinical knowledge and information-related barriers (OR: 0.59, 95% CI: 0.36-0.97). Conclusion: Strategies for improving clinical knowledge and providing expeditious information are necessary in order to improve community pharmacy services.