• Journal of Biosystems Engineering
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• v.34 no.3
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• pp.190-196
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• 2009

The temperature of root zone is known as an important factor for the growth of crops and reduction of energy in greenhouse. The purpose of this study was to design the solar energy supply system to keep the optimum condition of root zone by soil warming. As a result of this study, soil warming compared with no warming changed on a large scale temperature rise effect by depth of soil. The greenhouse's inner temperature have an effect on the temperature of surface up to 15 cm, rised to about 1 hour after warming. In case of the temperature fluctuation, soil temperature was about $12^{\circ}C$ up to 15${\sim}$25 cm and it was $13.4^{\circ}C$ at greater depths. This results showed that the position of root zone was very different after 3 weeks of growth.

• Resources Recycling
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• v.19 no.2
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• pp.63-72
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• 2010

The patents were searched to investigate the trend of recycling technologies about plastic waste. Database was collected from WIPS site and the range of the search was limited to patents opened in U.S.A (US), European Union (EU), Japan (JP) and Korea (KR) to september 2009. In this paper, 4,795 patents were selected by investigation abstracts and the trend of the recycling technologies relating to waste plastic were investigated through the analyzing by the years, countries, companies. The patents were occupied 65% by Japan and the most of the patents were about chemical recycling. In the case of Korea, material recycling was major in the patents of waste plastic recycling.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.50-60
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• 2007

There are several kinds of battery such as zinc-air battery, lithium battery, Manganese dry battery, silver oxide battery, mercury battery, sodium-sulphur battery, lead battery, nickel-hydrogen secondary battery, nickel-cadmium battery, lithium ion battery, alkaline battery, etc. These days it has been widely studied for the recycling technologies of the used battery from view points of economy and efficiency. In this paper, patents on the recycling technologies of the used lithium battery were analyzed. The range of search was limited in the open patents of USA(US), European Union(EP), Japan(JP), and Korea(KR) from 1986 to 2006. Patents were collected using key-words searching and filtered by filtering criteria. The trends of the patents was analyzed by the years, countries, companies, and technologies.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.1
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• pp.1-17
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• 2016

This paper attempts to explore the spatial structure of inventor networks and their determinants among 230 shi-gun-gu regions in Korea by investigating the residence of co-inventors engaged in Korean patent applications to the Korean Intellectual Office and exploiting a zero inflated negative binomial model to accommodate an estimation to the count nature of a dependent variable and its excess of zeros. Several variables are found to affect the spatial linkage of inventor networks. Spatial links extend beyond the region if it has more own R&D-related specific assets (private R&D, patent productivity, population, education); if it is physically close to and has technological similarity with the other region. The assets of the other region plays a positive role if, in a similar way, the other region has more R&D-related specific assets.

• Journal of Technology Innovation
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• v.26 no.3
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• pp.1-36
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• 2018

In the era of the 4th Industrial Revolution, it is important for companies to understand the changing environment by converging various technologies and to respond to the changing business environment. In this study, we conducted a social network analysis on 10 firms in the automotive industry, which have recently been accelerating their competition for technology development, by extracting convergence patents co-classified in two or more of the US registered patents in the last 6 years. As a result, it has been confirmed that the number of technology related to the convergence of the automotive field is greatly increasing, and the convergence between the technologies is becoming stronger. In addition, Volkswagen, Ford and Hyundai showed significant changes in technology convergence. They were analyzed as having a change in strategy in eco-friendly automotive technologies. This study suggests various ways for companies to utilize the results of network analysis more meaningfully.

• Resources Recycling
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• v.17 no.2
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• pp.76-84
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• 2008

There are several kinds of battery such as zinc-air battery, lithium battery, manganese dry battery, silver oxide battery, mercury battery, sodium-sulphur battery, lead battery, nickel-hydrogen secondary battery, nickel-cadmium battery, lithium ion battery and alkaline battery, etc. These days it has been widely studied for the recycling technologies of the used battery from view points of economy and efficiency. In this paper, patents on the recycling technologies of the used manganese dry battery were analyzed. The range of search was limited in the open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) from 1986 to 2006. Patents were collected using key-words searching and filtered by filtering criteria. The trends of the patents were analyzed by the years, countries, companies, and technologies.

• Resources Recycling
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• v.23 no.5
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• pp.68-79
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• 2014

Since 1990s, efforts to recycle the waste plastics by chemical methods have increased. And in accordance with this trend, attempts have become active to use the waste PET as raw materials of chemical industries. In this article, the patents and papers for development of commercial technology for feedstock recycling and high end products from PET wastes were collected and analyzed. The open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) and SCI journals from 1974 to 2013 were investigated. The patents and papers were collected using key-words and filtered by the definition of the technology. The patents and papers were analyzed by the years, countries, companies, and technologies and the technical trends were discussed in this paper.

• Resources Recycling
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• v.21 no.1
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• pp.82-92
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• 2012

There are several kinds of tungsten carbide(WC) such as light bulbs, metal cutting tools, drill bits, mining tools, military ordinance, high speed tool steels, chemicals/catalysts, wear resistance parts, jet engine turbine blades, etc.. These days it has been widely studied for the recycling technologies of the used tungsten carbide(WC) from view points of economy and efficiency. In this paper, open/registered patents of US, JP, EP, and KR and SCI Journal related to recycling technologies of the used Tungsten Carbide(WC) between 1969-2011 were reviewed. Patents and papers were collected using key-words searching and filtered by filtering criteria. The trends of the patents and papers was analyzed by the years, countries, companies, and technologies.

• Journal of Information Technology Applications and Management
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• v.19 no.4
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• pp.1-18
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• 2012

This paper identifies technology trends of national research and development (national R&D) by exploiting Korean national R&D patents, ranging from 2007 to 2010. In this paper, co-word analysis (CWA), which is a method to identify the relationship among technology terms by using their co-occurrences, is incorporated into network analysis to visualize the relationships among technology keywords of national R&D patents and calculate network indexes concerning inter-relationship diversity and strength of technology keywords. As a result, this research found that inter-relationship among technology keywords in national R&D are getting increasingly strengthening in an overall sense. In addition, the keyword inter-relationship diversity-strength map proposed in this paper revealed some significant technological keywords of national R&D : core technology keywords including "sensor", "film" and "fuel" and emerging keywords including "biosensor" and "thermoelectric". Because the proposed approach helps identify interdisciplinary trends of technology keywords from a massive volume of national R&D patents in a visual and quantitative way, we expect that the approach can be incorporated as a preliminary into the R&D planning process to assist R&D policy makers to understand technology convergence of national R&D and develop relevant R&D policies.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1530-1535
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• 2009

The cable bolt is useful underground space support system such as mining in Europe. In spite of favorable strength characteristics, past record of the cable bolt is rarely in Korea. In this study, to evaluate the mechanically characteristics the cable bolt on tunnel support system. To conduct the laboratory strength test in order to enquire material properties as reinforcement material and numerical analysis was performed considering laboratory test results. To estimate the behavior characteristics on tunnel system in which supported by the cable bolt system and compared the behavior characteristics with the rebar rock bolt system result.