Since 2011, a total length of national highway in Korea is 13,797km and 97.6% of total length of national highway system is paved. Particularly, most of national highway has been paved as asphalt concrete pavement. Currently, many maintenance techniques, such as overlay and surface treatments, are applied on existing pavements depending on the failure levels of pavements. One of maintenance techniques is a hot in-place recycling (HIR) that shows features of cost effective and better performance because of the use of 100% recycling of reclaimed asphalt of existing pavement. HIR is widely used in Europe countries and the U.S. It is recommended to rehabilitate the old and distressed asphalt pavement because it is suitable from the environmental perspective and convenient to use when a road is paved. Since 2002, HIR as a maintenance method has been used to rehabilitate the distressed asphalt pavement in National highway in Korea. Recently, a new HIR system, which consists of three pre-heaters, two recycler and one paver, is introduced in maintenance project in National highway. In this paper, HIR mixtures collected from a new HIR system in the field are tested to evaluate their performance in the laboratory test. First, the reclaimed asphalt (RAP) materials and HIR mixtures are collected in the field project site. Second, the quality evaluation of RAP materials, HIR mixtures and rejuvenator are conducted in the laboratory. Test results of RAP materials and HIR mixtures are satisfied with national specification. Rejuvenator used in the project site is classified as RA-5. Based on the limited teste results, it would be concluded that a new HIR system could be produced a satisfied HIR mixtures in the maintenance projects of National highway.

This study was conducted to determine the major patent and analyze the patent trend of unmanned and automated agricultural production for the open field operation. As a result of conducting a search for patent applications related to these technologies, 1,080 valid patents were selected by evaluating the relevance of the patents and removing noise patents. As a result of the country-based analysis using the selected valid patents, it was found out that the largest number of patent applications were filed in the United States with 541 cases, followed by Japan with 326 cases, the European Union with 128 cases, and Korea with 85 cases. Upon classifying the valid patents into core technology, the path generation and tracking technology accounts for 33% with 353 cases; the implementing control with environmental condition technology accounts for 22% with 236 cases; the robot design technology accounts for 21% with 228 cases; the plant and environment sensing technology accounts for 19% with 206 cases; the yield and quality monitoring technology accounts for 5% with 58 cases. Finally, 10 core patents were selected by performing a patent index evaluation. The United States registered all of the 10 core patents. The results showed that Korea falls behind in the open field-related unmanned and automated agricultural production, compared to other developed agricultural countries.