• Journal of Korean Society of Archives and Records Management
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• v.19 no.4
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• pp.1-33
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• 2019

The key to the long-term preservation of electronic records is the long-term retention of the bitstream that contains the original functional attributes and appearances of the electronic records that were originally created and utilized. Considering economic and technical aspects, most of the major domestic and foreign archives have adopted a migration strategy that allows conversion to a new format depending on the stability and reliability of the format containing the original bitstream. However, as the type of electronic records varies and its scope continuously expands, several problems arise if a single migration strategy is observed. Therefore, the applicability of the emulation strategy is examined in this paper to reproduce the system and application environment where electronic records are created and utilized. As such, electronic records can be maintained without any changes in the bitstream by utilizing cloud computing technology.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.451-456
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• 2018

UAVs (Unmanned Aerial Vehicles) are widely used for maintenance and monitoring of facilities. It is necessary to acquire a high-resolution image for evaluating the appearance state of the facility in safety inspection. In addition, it is essential to acquire the video data in order to acquire data over a wide area rapidly. In general, since video data does not include position information, it is difficult to analyze the actual size of the inspection object quantitatively. In this study, we evaluated the utilization of 3D point cloud data of bridges using a matching between video frames and reference photos. The drones were used to acquire video and photographs. And exterior orientations of the video frames were generated through feature point matching with reference photos. Experimental results showed that the accuracy of the video frame data is similar to that of the reference photos. Furthermore, the point cloud data generated by using video frames represented the shape and size of bridges with usable accuracy. If the stability of the product is verified through the matching test of various conditions in the future, it is expected that the video-based facility modeling and inspection will be effectively conducted.

• Journal of Convergence for Information Technology
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• v.11 no.7
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• pp.21-30
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• 2021

With the development of IoT technology, various cloud computing-based services such as smart cars, smart healthcare, smart homes, and smart farms are expanding. With the advent of a new environment, various problems continue to occur, such as the possibility of exposure of important information such as personal information or company secrets, financial damage cases due to hacking, and human casualties due to malicious attack techniques. In this paper, we propose a message communication protocol for smart home-based secure communication and user data protection. As a detailed process, secure device registration, message authentication protocol, and renewal protocol were newly designed in the smart home environment. By referring to the security requirements related to the smart home service, the stability of the representative attack technique was verified, and as a result of performing a comparative analysis of the performance, the efficiency of about 50% in the communication aspect and 25% in the signature verification aspect was confirmed.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.1
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• pp.343-364
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• 2021

In this study, as examples of domestic libraries currently using the cloud-based library system, the main characteristics and issues that appeared in the experience of use divided into the processes of introduction, conversion, and operation of each system were investigated, and the results are as follows. First, it is said that new systems were introduced as alternatives to problems caused by the operation of the existing system, and the current products were selected because they were cost-effective. Second, the main issues in the conversion process were data migration work, implementation of existing service functions, and linking problems of internal and external systems in the library. Third, the main advantages identified in the operation process were cost reduction, simple installation and automatic management and maintenance, and convenient use in mobile devices. The main drawbacks were the difficulty of customizing that reflects the characteristics of the library, and the need for stability of the network. The disappeared role of the information technology librarian is the regular system inspection and maintenance support, and various new roles have been suggested. The responses of librarians and users to the new system were generally satisfied rather than dissatisfied.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1225-1233
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• 2024

Level 3 probabilistic safety assessment (PSA) is performed to calculate radionuclide concentrations and exposure dose resulting from nuclear power plant accidents. To calculate the external exposure dose from the released radioactive materials, the radionuclide concentrations are multiplied by two factors of dose coefficient and a finite cloud dose correction factor (FCDCF), and the obtained values are summed. This indicates that a standard set of FCDCFs is required for external exposure dose calculations. To calculate a standard set of FCDCFs, the effective distance from the release point to the receptor along the wind direction should be predetermined. The TID-24190 document published in 1968 provides equations to calculate FCDCFs and the resultant standard set of FCDCFs. However, it does not provide any explanation on the effective distance required to calculate the standard set of FCDCFs. In 2021, Sandia National Laboratories (SNLs) proposed a method to predetermine finite effective distances depending on the atmospheric stability classes A to F, which results in six standard sets of FCDCFs. Meanwhile, independently of the SNLs, the authors of this paper discovered that an infinite effective distance assumption is a very reasonable approach to calculate one standard set of FCDCFs, and they implemented it into the multi-unit radiological consequence calculator (MURCC) code, which is a post-processor of the level 3 PSA codes. This paper calculates and compares short- and long-range FCDCFs calculated using the TID-24190, SNLs method, and MURCC method, and explains the strength of the MURCC method over the SNLs method. Although six standard sets of FCDCFs are required by the SNLs method, one standard sets of FCDCFs are sufficient by the MURCC method. Additionally, the use of the MURCC method and its resultant FCDCFs for level 3 PSA was strongly recommended.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1425-1434
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• 2021

Continuous and periodic data acquisition must be preceded to maintain and manage the river facilities effectively. Adapting the existing general facilities methods, which include river surveying methods such as terrestrial laser scanners, total stations, and Global Navigation Satellite System (GNSS), has limitation in terms of its costs, manpower, and times to acquire spatial information since the river facilities are distributed across the wide and long area. On the other hand, the Mobile Mapping System (MMS) has comparative advantage in acquiring the data of river facilities since it constructs three-dimensional spatial information while moving. By using the MMS, 184,646,009 points could be attained for Anyang stream with a length of 4 kilometers only in 20 minutes. Levee points were divided at intervals of 10 meters so that about 378 levee cross sections were generated. In addition, the waterside maximum and average slope could be automatically calculated by separating slope plane form levee point cloud, and the accuracy of RMSE was confirmed by comparing with manually calculated slope. The reference slope was calculated manually by plotting point cloud of levee slope plane and selecting two points that use location information when calculating the slope. Also, as a result of comparing the water side slope with slope standard in basic river plan for Anyang stream, it is confirmed that inspecting the river facilities with the MMS point cloud is highly recommended than the existing river survey.

• Atmosphere
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• v.22 no.2
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• pp.209-219
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• 2012

Extreme heavy snowfall episodes have been investigated in case of accumulated snowfall amount larger than 50 cm during the past ten years, in order to understand the association of low-level stability with heavy snowfall in the Yeongdong region. In general, the selected 4 events have similar synoptic setting such as the Siberian High extended to East Sea along with the Low passing by the southern Korean Peninsula, eventually inducing easterly in the Yeongdong region. Specifically moist-adiabatically neutral layer has been observed during the heavy snowfall period, which was easily identified using vertical profiles of equivalent potential temperature observed at Sokcho, whereas convective unstable layer has been formed over the East sea due to relatively warm sea surface temperature (SST) about $8{\sim}10^{\circ}C$ and lower temperature around 1~2 km above the surface, obtained from RDAPS. Difference of equivalent potential temperature between 850 hPa and surface as well as difference between air and sea temperatures altogether gradually increased before the snowfall period. Instability-induced moisture supply to the atmosphere from the East sea, being cooled and saturated by the upper cold surge, would make low-level ice cloud, and eventually move inland by the easterly flow. Heavy snowfall will be enhanced in association with low-level convergence by surface friction and upslope wind against Taebaek mountains. This study emphasizes the importance of low level stability in the Yeongdong region using the radiosonde sounding and RDAPS data, which should quantitatively be examined through numerical model as well as heat and moisture supply from the ocean.

• Tribology and Lubricants
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• v.17 no.2
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• pp.146-152
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• 2001

Environmentally adapted synthetic base oils of polyalkylene glycols (PAGs) and polyol esters (POEs) show a high polarity because of their functional groups containing oxygen atom. The lubricating performance of these polar base oils was investigated by using a four-ball tribometer under boundary lubrication condition. Four polyalkylene glycols and five polyol ester base oils were used as sample base oils of high polarity. A mineral oil (MO) and alkylnaphthalene (AN) were used as low polarity base oils. Tricrecylphosphate (TCP) was added to all the base oils, in the range of 10 mmol/L-2000 mmol/L, as an antiwear additive. All the TCP-for-mutated base oils showed optimum concentration characteristics for minimizing wear. The order of optimum concentration of all the base oils was in a good accordance with the order of relative stability of TCP in base oils. The interaction model on solvation between additive and different polar base oils can expect the stability order of TCP. Thus, the model on solvation can explain well the order of optimum concentration of all the base oils, by using the effect of polarity (dielectric constant, $\varepsilon$) and molecular size (molecular weight, MW) of them on stability of TCP in polar base oils. Finally, a good correlation of the optimum concentration for all the base oils was obtained when it was arranged as a function of C∝(M $W_{Base Oil}$/M $W_{TCP}$)$^{-2}$.71/.($\varepsilon$$_{Base Oil}$)$^{3.38}$ by these two parameters.s..

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.727-742
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• 2020

Point cloud-based 3D maps can obtain many kinds of information for maintenance work on forest road networks. This study was conducted to compare the importance of each factor to select the factors required for the mapping of 3D forest road maps. This can be used as basic data for attribute information required to maintain forest road networks. The results of this study found that out of a total of 30 indexes extracted for mapping 3D forest roads, a total of 21 indexes related to stakeholder groups were significantly different. The importance of the index required by the civil service group was significantly higher than that of the other groups overall. In the case of the academic group, the index importance for cut slope, fill slope, and drainage facility was significantly higher. On the other hand, the index importance for the forestry cooperative and forest professional engineer group was mostly distributed between the civil servants' group and the academic group. In particular, the type of drainage system showed the highest value among the detailed indexes. Overall, drainage related factors in this survey had high coefficient values. The impact of water on forest roads was the most important part in road maintenance. In addition, the soil texture had a high value in relation to slope stability. This is thought to be because the texture of the soil affects the stability of the slope.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.666-672
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• 1995

This study was carried out to characterize thermolabile pectinesterase (TLPE) and thermostable pectinesterase (TSPE) separated from crude PE of Valencia orange in order to investigate the preventive measures of cloudy juice clarification. The TLPE was observed to be mixture of several isoenzymes with the same molecular weight of 36 KD (37.5 KD) but different isoelectric point of pH 8.4, 8.7, 8.9, 9.8 and ${\geq}10$ which were unstable at $70^{\circ}C$, and the TSPE also was found to be mixture of two or three isoenzymes with the same molecular weight of 53 KD (50 KD) but different isoelectric point of pH 8.7, 9.2 and ${\geq}10$ which had slightly different stability from one another at $70^{\circ}C$. The TLPE and the TSPE had the optimum reaction pH of 7.0 and $7.0{\sim}8.5,\;appK_{M}$ of 1.1 and 1.7 mg/ml, appVmax of 0.53 and $1.01\;{\mu}mol/min/{\mu}g$, and the turnover number of 19.000 and 54,000 mol/mol/min toward Kodak pectin, respectively. The TSPE had higher storage stabiblity and cloud loss effect on orange juice than the TLPE. Above all, the crude PE was most effective on orange juice cloud loss among the PEs used.