• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.29-36
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• 2022

In this paper, we propose an efficient agricultural products price prediction model based on dataset which provided in DACON. This model is XGBoost and CatBoost, and as an algorithm of the Gradient Boosting series, the average accuracy and execution time are superior to the existing Logistic Regression and Random Forest. Based on these advantages, we design a machine learning model that predicts prices 1 week, 2 weeks, and 4 weeks from the previous prices of agricultural products. The XGBoost model can derive the best performance by adjusting hyperparameters using the XGBoost Regressor library, which is a regression model. The implemented model is verified using the API provided by DACON, and performance evaluation is performed for each model. Because XGBoost conducts its own overfitting regulation, it derives excellent performance despite a small dataset, but it was found that the performance was lower than LGBM in terms of temporal performance such as learning time and prediction time.

• Journal of Information Management
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• v.33 no.1
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• pp.81-95
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• 2002

The Department of Energy's (DOE) Scientific and Technical Information Program (STIP) has successfully reinvented the way in which DOE collects, organizes, archives, disseminates, and uses scientific and technical information in the performance of research and development (R&D). Through a suite of innovative Web-based products conceived and developed by the Department's Office of Scientific and Technical Information(OSTI), information and resources resulting from the Department's R&D activities, as well as worldwide information needed by the research community, are readily available to all users in a fully integrated E-Government environment. This suite of products is accessible publicly at .

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.3
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• pp.8-21
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• 2015

Technology for electric lighting has been evolving from Incandescent Lamp(IL) through Fluorescent Lamp(FL) and currently to Solid State Lighting(SSL) such as LED for more than 130 years of time. However, it took more than 100 years until the transition from IL to FL across overall society. That is because the transition is the Socio-Technical Transition(STT) which involves various social elements. This study investigated and analyzed the theories regarding STT, and applied the Multi-Level Perspective(MLP) theory to the case of electric lighting. A qualitative contents analysis was used with secondary data as research method, and the analyzed result was visualized based on the frame of MLP theory. The STT of electric lighting from IL to FL took place as the order of Technical Niche, Socio-Technical Regime and Landscape. Specifically, in Technical Niche level: Establishing Market Niche, Price-Performance Improvement, Learning Process and Support of Powerful Group took place. In Socio-Technical Regime level: Changes in Social Network, Changes in Technology and Changes in Rules. In Landscape level: Macro-Political Development, Socio-Economic Trends and Macro-Economic Trends took place in consecutive order.

• Journal of Information Technology and Architecture
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• v.9 no.2
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• pp.199-207
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• 2012

This study analyzed how the subcontracting business relations and structures of cooperation affect the relationship skills (Outcome) that is divided into three steps. We analyzed integrated data every other year from 2005 to 2009. As a results, in the execution of technical cooperation trade relations have influenced the positive attributes, but recently their influence has been weakened. As for technical cooperation, the structure should alleviate the problem of the uneven performance of technical cooperation. We suggested that technical expertise and infrastructure make possible the culmination of the long-term technological competitiveness level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6517-6526
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• 2015

This study analyzes the technical level and shows the priority technology for suspension bridges that play an iconic role as the country's landmark and contain an economic value. Analysis results show the technical level of suspension bridge is 82 percent compared to developed countries. In detail, the technical levels of 'materials', 'planning and design', and 'construction and maintenance' are 80.2 %, 81.7%, and 83.7% respectively. This study analyzes economic, social, technical importances and presents 'high-performance packaging material' as a priority technology.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.510-516
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• 2009

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were measured in soil samples of Ansung in Kyonggi-province to investigate concentration distribution of PBDEs and PCBs. The 10 soil samples were collected using a stainless steel hand-held corer that was cleaned before and after each sample using hexane. Total concentration of PBDE and PCBs were 2,205.3 and 348.1 pg/g dry weight (DW) in soil sample, respectively. BDE-209 showed as the most abundant congener in soil samples which was related to imported amount and usage amount of deca-BDE technical mixture in Korea. Also, BDE-99, BDE-47, BDE-100 deposition in soil sample was higher than other congeners and was related to the imported and usage amount reported for penta-BDE technical mixture in Korea. Correlation coefficient between PBDE contribution and technical mixture formulation (Bromokal 70-5DE) were significant (r=0.91, p<0.01) which suggests the influence of sources in this technical mixtures.

• 한국디지털정책학회:학술대회논문집
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• 2006.12a
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• pp.19-41
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• 2006

The purpose of this paper is to suggest field-oriented policy of regional innovation support system. To accomplish this purpose, we examined the status quo of technical support ,performance satisfaction of consumers and practical issues. The key factors influencing core technical innovation of small and medium firms are development fund, R&D employees, experimental instrument, technical information, protection of intellectual property, subcontracting and so on. To make sure of practical effect, therefore, it would rather necessary to implement policy support linking government and supporting means on the ground of needs of small and medium firms than specific method such as funding.

• Steel and Composite Structures
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• v.7 no.3
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• pp.241-251
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• 2007

The purpose of this study is to calculate the torsional rigidity of arbitrarily shaped composite sections on the basis of hybrid finite element approach. An analogy is used between the torsion problem and deformation of a plate which exhibits only shear behavior. In the analysis a simple hybrid finite element based on Hellinger-Reissner functional is presented and a set of numerical examples are performed to demonstrate and asses the performance of the developed element in practical applications.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.337-340
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• 2009

In general, channel information of received DTV signal analyzed based on symbol timing clock with only In-phase information in DTV receiver. This paper presents technical requirements of channel analysis system for DTV reception signal. In order to meet such requirements and measure more accurate magnitude and phase of channel information, compensation method for the quadrature information from measured in-phase data is proposed. The proposed channel analysis system is implemented with a commercial DTV chipset and provides fast data analysis with good connectivity with field test vehicles. Computer simulation and laboratory test results are provided to figure out the performance of the proposed channel analysis system for DTV signal.

• Journal of Digital Convergence
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• v.5 no.1
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• pp.101-116
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• 2007

The purpose of this paper is to suggest field-oriented policy of regional innovation support system. To accomplish this purpose, we examined the status quo of technical support, performance satisfaction of consumers and practical issues. The key factors influencing core technical innovation of small and medium firms are development fund, R&D employees, experimental instrument, technical information, protection of intellectual property, subcontracting and so on. To make sure of practical effect, therefore, it would rather necessary to implement policy support linking government and supporting means on the ground of needs of small and medium firms than specific method such as funding.