• Korean Journal of Microbiology
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• v.42 no.2
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• pp.156-159
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• 2006

A base substitution was introduced at the position 789 in Escherichia coli 16S rRNA, which was previously identified as an invariant residue for ribosome function and the ability of the mutant ribosomes to translate chloramphenicol acetyltransfernse mRNA was measured by determining the degree of resistance to chloramphenicol of cells expressing these mutant ribosomes. As expected, mutant ribosomes containing a base sub-stitution at the position 789 showed significantly reduced protein-synthesis ability and to identify a functional role played by this residue in protein synthesis, we developed an efficient genetic method to select second-site revertants in 16S rRNA that restore protein-synthesis function to these mutant ribosomes.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.15-22
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• 2019

In this paper, a global and local flight path system for autonomous flight of the UAV is proposed. The overall system is based on the ROS robot operating system. The UAV in-built computer detects obstacles through 2-D Lidar and generates real-time local path and global path based on VFH and Modified $RRT^*$-Smart, respectively. Additionally, a movement command is issued based on the generated path on the UAV flight controller. The ground station computer receives the obstacle information and generates a 2-D SLAM map, transmits the destination point to the embedded computer, and manages the state of the UAV. The autonomous UAV flight system of the is verified through a simulator and actual flight.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.623-629
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• 2018

In this paper, we propose a real-time obstacle detection and avoidance path generation algorithm for UAV. 2-D Lidar is used to detect obstacles, and the detected obstacle data is used to generate real-time histogram for local avoidance path and a 2-D SLAM map used for global avoidance path generation to the target point. The VFH algorithm for local avoidance path generation generates a real-time histogram of how much the obstacles are distributed in the vector direction and distance, and this histogram is used to generate the local avoidance path when detecting near fixed or dynamic obstacles. We propose an algorithm, called modified $RRT^*-Smart$, to overcome existing limitations. That generates global avoidance path to the target point by creating lower costs because nodes are checked whether or not straight path to a target point, and given arbitrary lengths and directionality to the target points when nodes are created. In this paper, we prove the efficient avoidance maneuvering through various simulation experiment environment by creating efficient avoidance paths.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.117-133
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• 2023

This study assessed the ecological health of border areas using the ecological health index and suggested Indicators for maintaining and promoting ecological values. We analyzed the change trends, pressures, and resilience of ecosystems and services in border areas, and identified their current status and sustainability. The main findings were: (1) ecological assets and ecosystem services in border areas could be compared through ecosystem health assessment; (2) it can be used to set priorities for management and conservation by identifying the relative importance and vulnerability of ecosystems and ecosystem services in each border area; and (3) the index presented in this study can be judged to have explanatory power for the characteristics of border areas and ecosystem health when compared to previous studies. Limitations of this study include the lack of literature and statistical data at the local government level and the resulting limited application of evaluation methods, which limited direct regional comparisons. To overcome the research limitations, further studies are needed, such as establishing ecological information in border areas, mapping and assessment of ecosystem services, and developing and applying assessments that reflect the opinions and participation of various stakeholders. This study was the first attempt to assess the health of ecosystems and ecosystem services in border areas and provided an important baseline for future changes in border areas. In the future, it will be helpful in national and local government policies and ecological assetecosystem management by supplementing insufficient information and presenting clear goals.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.1
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• pp.1-14
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• 2020

Various policies and studies regarding use of PBSS (Public Bike Sharing System) and Programs (PBSP) have been conducted worldwide as the number systems or programs has increased. Although various phenomena and demands have been generated by the use of PBSS in everyday life, the majority of research and the policies in South Korea have been implemented focused on commuting life. The purpose of this study aimed to understand various PBSS demands using PBSS usage data in 2018 in the Yeouido districts through classifying usage patterns and analyzing features. The rental stations were classified into three types based on weekday/weekend usage rates. The usage of Yeouido's PBSS accounted for 4.3% of the total usage in Seoul Metropolitan City, while the number of PBSS rental stations accounted for 2% of all rental stations in the Seoul urban areas. Rental stations with a higher weekday utilization rates showed high utilization rates in all four seasons and were mainly distributed in work and residential areas. Other stations showed a concentrated usage pattern in spring (April-May) and autumn (September-October) seasons, and their locations were close to the entrance of nearby parks. Besides, renting and returning were often concentrated at certain rental stations for high weekend utilization as compared to the pattern of high weekday usage. Therefore, PBSS management and programs should be operated to reflect various usage demands rather than uniform PBSS operations. The result of this study is meaningful to provide basic data for effective PBSS operation by monitoring the demand for PBSS usage in spatio-temporal terms.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.3
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• pp.1-11
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• 2020

Urban parks are important spaces of ecological and socio-cultural value to citizens who lead busy lives in increasingly complex and densely populated megalopolises. However, creating and maintaining city parks takes the will of the authorities to put it into practice and provide the attendant financial resources. That explains why we are focused on the budget aspects for the Seoul Metropolitan City in relation to creating park spaces. Our findings were as follows: 1) The overall city budget has steadily increased, but the budget allocated to Green Seoul Bureau and new park development has decreased since 2011. 2) As for elected officials, the budget grew during the time of the first, third, and fourth mayors as the creation of parks was considered to be a major priority, but after the sixth popularly elected mayor, the budget was sharply cut. 3) About 10% of the budget was allocated to the parks managed by the self-governing districts, compared to the ones under the direct management of the city. Furthermore, the analysis of the average annual budget for each park and how long (in terms of year) the budget for each park is invested showed that it was classified into three different types of category. Local governments adhere to the principle that their budget must be compiled and expended for a single year, which makes it hard to establish and push ahead with a long-term plan. However, as parks and green areas should not be approached from a short-term perspective for performance but from a long-term perspective, securing the consistent amount of budget is essential. This study has significance in that it attempted to analyze the budget issues related to parks, which has not been studied in depth so far, but the subject in this paper was limited to the budget for Green Seoul Bureau. Therefore, further research is needed because the parks managed by the self-governing districts were not considered.

• Food Science and Preservation
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• v.6 no.2
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• pp.148-152
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• 1999

Philippine bananas were ripened at various temperatures(18$^{\circ}C$, 21$^{\circ}C$ and 25$^{\circ}C$) for 5 days and stored at 13$^{\circ}C$ and ambient temperature(13-20$^{\circ}C$) for 16 days. Their quality changes were evaluated during the storage. The color chart number and soluble solids of bananas before storage showed 4.2-5.2 and 18.7-18.8$^{\circ}$ Bx at 18$^{\circ}C$ and 21$^{\circ}C$ ripening and 5.5 and 20.1 $^{\circ}$Bx at 25$^{\circ}C$ ripening, respectively. Weight losses reached about 1% around 10 days in all storage conditions. Soluble solids increased initially for 4-6 days and then decreased slightly. Color chart number changed from 4.2-5.5 after ripening to 7 after 2-4 days storage. Blackening of 18$^{\circ}C$ and 21$^{\circ}C$ ripened bananas occurred after 4 days storage at 13$^{\circ}C$ and after 2 days storage at ambient temperature. Decay of 18$^{\circ}C$ and 21$^{\circ}C$ ripening bananas increased from 2.1% after 6 days at 13$^{\circ}C$ storage and 4.2% after 4 days at ambient temperature storage to 75-100% within 2-4 days after that times. The decay of 25$^{\circ}C$ ripened bananas rapidly increased after 2 days at 13$^{\circ}C$ storage and at the initial at ambient temperature storage.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.218-223
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• 1981

This study was conducted to investigate the effects of post-harvest drying method and subsquent storage condition on the quality of garlic bulbs for 10 months from July, 1980 to April, 1981. The 27% weight loss of garlic bulbs by HPHD (hot air post-harvest frying) for 12 days at $40^{\circ}C$ (8hrs/day) was equal to that by NPHD (conventional natural post-harvest drying) for 35 days. But the decay occured 5.5% only in NPHD. During the storage period of garlic bulbs by HPHD, their decay and weight ]oss were less 25.4% and 13.5% in ambient storage, and less 14.2% and 7.5% in low temperature storage than those of NPHD. When garlic bulbs were stored in low temperature, the weight loss and decay were less 20.0% and 22.4% in NPHD, and tess 14.0% and 9.9% in HPHD than those in ambient temperature storage. The Quality of garlic bulbs packed with 0.08mm polyethylene film stored at ambient temperature for 2 months was so poor as to be inedible because of the adverse effect of $CO_2$ and the growth of molds, but in low temperature storage for 10 months it was in good shape showing the weight loss, the decay and the sprouting 2.6%, 3.4% and 26.8%, respectively.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.150-154
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• 1990

Various sterilization temperatures $(110^{\circ}C,\;120^{\circ}C,\;130^{\circ}C)$ and air volumes (air, 31ml, half-vacuum; 13ml, vacuum; -0.7ml) within the retort pouch were tested for the development of the simple retort rice processing techniques in which the pouch were filled with rice and water, and then sterilized. Water content of retort rice was found to be 59.0-63.3% resulting from mixing the rice and water in the ratio of 1:1.1. The most uniform water content was obtained from retort rice sterilized at $130^{\circ}C$ and packaged under vacuum. The larger water content differences were observed with the increase in internal air volumes within the retort pouch. Spreading degree of retort rice was geater than that of general cooked rice, was lower in upper layer than in low layer, and became lower with the larger air volume and higher sterilization temperature. a degree of rice became higher with the Increase of sterilization temperature but that was not affected by the internal air volume of the pouch. The higher sterilization temperature and the lower the air volume, the higher the whiteness was. The highest whiteness was obtained by packaging under vacuum and sterilizing at $130^{\circ}C$. Intact degree was much higer in packaging under air than vacuum. In sensory evaluation the retort rice of vacuum pack was good in color and spreading degree but not in appearance because of blocking and deforming, but that of air pack was good in texture on the contrary. The best quality was obtained by packaging under half-vacuum and sterilizing at $130^{\circ}C$.

• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.20-26
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• 2018

In this paper, we propose a moving object detection and tracking algorithm based on multi-frame feature point tracking information to reduce false positives. However, there are problems of detection error and tracking speed in existing studies. In order to compensate for this, we first calculate the corner feature points and the optical flow of multiple frames for camera movement compensation and object tracking. Next, the tracking error of the optical flow is reduced by the multi-frame forward-backward tracking, and the traced feature points are divided into the background and the moving object candidate based on homography and RANSAC algorithm for camera movement compensation. Among the transformed corner feature points, the outlier points removed by the RANSAC are clustered and the outlier cluster of a certain size is classified as the moving object candidate. Objects classified as moving object candidates are tracked according to label tracking based data association analysis. In this paper, we prove that the proposed algorithm improves both precision and recall compared with existing algorithms by using quadrotor image - based detection and tracking performance experiments.